Template talk:Inflation/Archive 1

New template: Inflation

 * → This discussion started at the template author's talk page and was moved here for template users' convenience.

Great work! I would like to adapt this template to the German wikipedia, if you agree. To do so I need to add the inflation rate for DM/Euro. Would it be usefull to add this currency also in the english template? I provide you with the figures in the hidden text to keep the page readable.Karsten11 (talk) 18:26, 26 May 2008 (UTC)


 * Sure! Both for you adapting it to the German Wikipedia and for me adding DM and Euro it. In fact, adding a new currency is pretty easy, although I think I'll change the structure so that individual currencies are stored in individual pages, for an easier maintenance.


 * But first tell me: do these numbers take into account the change in currency, so that values in DM get automatically converted to Euros if I simply go multiplying year after year? Or will an input in DM also output in DM? Because I think the best thing is for currencies to not be converted, requiring the user to do a conversion by hand, as it would be quite difficult to keep track of which currency was valid for which year.


 * Also, could you please provide me a list for Euro-only inflations? If I'm going to add the older DM, it's fair I also add the Euro itself in the same move. :-)


 * And what about Germany before 1951? Is data available? -- alexgieg (talk) 00:22, 27 May 2008 (UTC)

Individual currencies in individual pages seems to be a good approach. Only for the german wikipedia we have DM/Euro for Germany, ÖS/Euro für Austria and SFR for Switzerland (and need the exiting USD and GBP too).

There are 3 phases: a) 1951 to 1998: In this phase only DM exists. So each value in articles describing an amount must be in DM. Today DM is history. So these amounts need to be inflation-adjusted and changed into Euro (1 Euro = 1,95583 DM). b) Between 1999-01-01 and 2001-12-31 DM and Euro exists in parallel. So the amount in the article can be given in DM or Euro. Only in the first case it needs to be converted. c) From 2002 we use only Euro. No conversion is needed. An Output schould be everytime in Euro. A manual conversion is possible but not user-friendly. May be we can make the calculation much easier by taking an assumtion, that all amounts in phase b are in DM.

There is no Euro-only inflation. In Europe we measure inflation by country. Even if Germany as well as Ireland use Euro, we have a different inflation rate for both countries. So we have a Inflation rate for Germany, not for the currencies.

Historical inflation rates are a problem. After WW II there was a hyperinflation. The former currency (German Reichsmark) lost the value and was replaced 1948 by the DM. The inflation rates in the 1940s was so high that it would be necessary to know in which month or week the amount was payed to use the right factor. And: Due to the war the quality of the statistics is rather poor. For the time between 1924 an 1940 inflation rates are available. Ther we would need a factor to link the 1940 value with the value of 1951. This is not easy. 1922/23 there was also a hyperinflation with inflation rates which are not usable. In advance there was the German gold mark. If we can link 1924 and 1921 than we can go back to 1876 when the Goldmark was initialy issued. You can see: It´s a little tricky with german currencies.Karsten11 (talk) 06:20, 27 May 2008 (UTC)


 * Thanks for the information. I've been thinking about this since yesterday, and my conclusion is that it would be very difficult to correctly implement currency conversion in this template. Even if I design a system that makes it easy for the European countries with the Euro, other countries might have much more convoluted situations, and adding a special case for each one, with extra variables that would have different meanings in each case, wouldn't be a good solution. So, my option is to change the template in the following way: it will be currency-agnostic, taking as first parameter not a currency code, but a country code. Later, I or someone else could develop specific currency-conversion templates to take care of the stranger details. This is what such a solution might look like:


 * 


 * This is better, IMHO, because the editor wanting to show in an article how a certain value updates already knows in which currency the original value is (why would he want to know its updated value otherwise?), and in which currency he wants to see the result (it's him who ends up writing the currency symbol before the "formatnum" result anyway). So, since he can himself knowledgeably select these things, there's no point in guessing for him.

It would be helpful to round the results to 2 positions after decimal point.Karsten11 (talk) 11:39, 27 May 2008 (UTC)


 * This isn't a good idea because of the way MediaWiki produces the results of calculations. You can make a calculation with two positions after the decimal point, but you can't guarantee that the output will contain two digits. For example, if the result was 1234567.8, "formatnum" would show it as "1,234,567.8", not as "1,234,567.80". And since MediaWiki also doesn't provide any advanced string manipulation functions, there's no way to optionally insert that missing "0". So, the best I came with was to do an integer calculus. At least integers don't usually come with missing digits.


 * And I say "usually" because if MediaWiki decides to present the result in engineering units (for example, "1E+9"), "formatnum" gets completely lost, and there's no way to convert it back to "1,000,000,000" either. It's all very limiting, unfortunately... :-(


 * PS.: By the way, would you mind if I moved this discussion to the template's talk page? I think it's better to have this talk there, so that others looking at the template itself might know what's going on behind it. -- alexgieg (talk) 18:30, 27 May 2008 (UTC)

This Currconv sounds good. This template can be used in combination with inflation template as well as stand-alone. You are right: The template discussion page is the right place for this discussion.Karsten11 (talk) 08:48, 28 May 2008 (UTC)


 * In the de:wikipedia the template has been implemented (de:Vorlage:Inflation) We decided on 2 changes compared with the en-version: The conversion from DM to Euro is to be done automatical using the inflation rate of 2001. So a Currconv template is not requested any longer and the complexity of the template has not increased. The second thing is, that we dont link on NaN if a parameter is wrong but defined an template-specific error page.Karsten11 (talk) 11:25, 1 June 2008 (UTC)


 * Hmm... I like the idea of providing a template-specific error page or message. As for Currconv, I have plans of making it as a fully fledged currency converter template, not only between Euro and pre-Euro currencies, but between any two currencies, accepting an year parameter much like Inflation does. But if a version with a default, hard-coded conversion is better for use in the German Wikipedia, that's nice too, as I can see how it would be cumbersome to add explicit conversions there. -- alexgieg (talk) 15:33, 6 June 2008 (UTC)

Hallmark!
I'd like to inform that Slavery has just became the very first (actual) article in Wikipedia using this template!

The previous, hard-coded version informed that the price for a slave in the USA of 1850 ($1,000) would be "about US$38,000 in present-day terms". After changing it to the dynamically generated, though, it now shows the much more accurate "about US$0 in present-day terms".

As this template is updated year after year, articles properly edited to take advantage of it will be automatically update too. What could be better for an online encyclopedia which has the moral obligation of staying accurate? So, let's start editing articles accordingly! It's more than worth the effort!

But a reminder: take care to not change hard-coded values present in citations or from referenced sources. Only values whose source is a Wikipedia editor should be turned into a dynamically generated ones. Otherwise, obviously, those citations would become invalid and the edit would have to be reverted.

Have fun! -- alexgieg (talk) 14:30, 28 May 2008 (UTC)

Template Inflation-fn
I've created a new template,, that makes it easy to add footnotes referencing the source of the data used for calculating inflated values. By using it you'll make the article you're editing even more WP:V compliant. See the new documentation section for a typical usage example. -- alexgieg (talk) 16:30, 30 May 2008 (UTC)

Template Formatprice
I've made another cool template: Formatprice. It avoids the cents problem in the built-in, while adding some nice capabilities for displaying huge numbers. I've just updated the documentation to explain how to use it in addition to the previous method. Give it a look! -- alexgieg (talk) 15:36, 6 June 2008 (UTC)

No downside
On the down side, Formatprice has no built-in intelligent handling of user locale settings, what means that some users might see a dot or a comma the opposite way they'd expect.

I'd say that this is no downside. It's a question of language not location. In English it's a dot for the decimal point and commas (spaces or nothing at all) for thousands delimitation. In Germany English should still be English. Please don't "solve" this non-problem. J IM ptalk·cont 23:41, 8 June 2008 (UTC)


 * Hehe, okay, I'll try not to, although I don't think it's even possible. :-) -- alexgieg (talk) 13:37, 9 June 2008 (UTC)

Various points
Obviously this is a useful starting point for an unflation template: US Inflation is the only preexisting one and is focussed on the single task of inflating USD to current prices. There are a number of issues I can see with this template, some minor quibbles, some quite serious. Ultimately, I'd like to be able to redirect US Inflation to call here, but because of those concerns I'd rather not at this time. Anyway problems in roughly descending order: That's a few things to be getting on with, though point 1 needs to be dealt with: either by changing the source of the info or getting permission to use their data. Oh and here is Canadian CPI data for 1914 - present.--Nilfanion (talk) 22:53, 10 June 2008 (UTC)
 * 1) Copyright: The German information is from the Federal Government, as I can't read German I can't verify if there are any restrictions. However, Measuring Worth asserts copyright, and its terms of use are too restrictive for Wikipedia: We would require commercial re-use. I'm not totally sure if copyright is a concern, but as they both assert copyright and we use their data verbatim its a problem.
 * 2) Technical: Inflation/UK (and /US and /DE) calculates the multiplication factor by chaining the year by year inflation. This is over-complicated as the sources provide each years index but not the percentage from year to year. The fact that the raw figures are rounded means rounding errors may occur too. It is also needlessly heavy on system resources: To calculate requires MediaWiki to evaluate nearly 800 Ifs and then do a multiplication with 700 arguments. A much simpler method would be similar (but not identical) to how US Inflation handles things.
 * 3) Have the sub-templates as giant #switch: statements, with each year listing the Index value from the source.
 * 4) Work out the factor by doing the calculation Index in final year / Index in initial year. For instance, (for USD) for 2000 to 2005 this would be 195.3 / 172.2 ~ 1.13.
 * 5) This requires 2 calls of a switch, a division with two arguments and then a multiplication by the required amount: 4 calculations as opposed to 1500.
 * 6) This would also make deflation from 2005 to 2000 trivial: If the years were swapped, the factor would be inverted - with the desired end result.
 * 7) Data quality: The German data is from the German government, so can surely be assumed to be correct. However the UK and US data comes from a private organisation, and in my experience I've never seen two inflation calculators agree. US Inflation uses data from the Federal Reserve Bank of Minneapolis, and for 1914 and 2000 their CPI Index figures are 10.0 and 172.2. Measuring Worth's values for the same time are 9.69 and 172.2. This means using Measuring Worth figures produces an inflation over that period which is 3% higher than using figures from the Fed. Which is more accurate? Personally, I'm inclined to go with the government source. Furthermore, what is the sourcing Measuring Worth used to generate all their older figures? If the sources are unreliable, so is the data.
 * 8) Minor stuff. "400 billion" should be written with a non-breaking space. It would be better to have the subpages at the ISO 4217 codes and not country codes: This allows for multiple currencies in the same nation if required in the future.


 * Very good points. I'll have a look at improving the template according to your suggestions over the next few days. Thank you very much for taking the time to help make this alpha template (because that's what it is) a better one. :-)


 * About point #1: I'm not quite sure their restrictions apply, since as far as I know neither pure facts, nor mathematical equations, are copyrightable, but I'm no copyright law expert, so I might be wrong. In any case, sure, official data is preferable. I see no problem in switching the base data set to the one you suggest.


 * About point #4: Originally I made this template using currency codes. In fact, you can still use "USD" and "GBP" as codes, they are now redirects to "US" and "UK". However, another user pointed out (see the first thread above) that this doesn't work for EUR, as each European country has its own, independent inflation rate. Thus, a median inflation over a geographical region seemed to us both more in line with the way inflation actually works in practice than the average over a currency itself. But in fact nothing prevents the template from accepting both kinds of codes. Most of the time a currency would be a redirect to an area (or the other way around), with only a few exceptions. EUR itself would be such an exception, as its data set would end up being an average of the individual European Union countries' inflations. -- alexgieg (talk) 02:42, 11 June 2008 (UTC)


 * I'm not sure about copyright either, but its something to be aware of (I'm not going to attempt to determine if the copyright assertion on their pages is copyfraud or not). As for the location of the subpages: 200DM (1960) is not 748 in 2005, as the Deutschmark no longer exists, and as that clearly isn't the Euro value, that is asking for confusion. There is Eurozone wide CPI data, which would obviously be at EUR. Perhaps, the template should realise that wants to cross the currency changeover and incorporate the 1.95583 conversion in its result automatically when required. Certainly the documentation needs improving, so that users know what will happen when they cross a currency change will it produce a DM figure that they will need to convert to Euros manually or will it do that for them? If I want a  One thing that would be very useful would be if the template could accept greater granularity if provided. That said, I can't see a practical way to do that.-Nilfanion (talk) 10:15, 11 June 2008 (UTC)

See the above discussion about the currency crossing. In short, I'm against it because there are technical difficulties. In Europe there was a period when both the national currency and the EUR existed. To properly incorporate currency conversion in the inflation template itself would mean either: a) adding extra parameters to deal with overlapping currencies, what can easily become an extreme level of complexity to the template once more countries (and maybe currencies) with their own oddities enter the template; or b) arbitrarily setting a threshold, as you suggest. I myself prefer neither, going instead with c) creating a separate template (currently non-existent), named Currconv, to deal exclusively with currency conversions. Thus, if an editor wanted values to be converted between currencies, he could wrap it into something like this: . No need to go around guessing for him.

Of course, the other approach is also perfectly valid. Karsten11, with whom I talked about this all, decided to implement the German version of this template differently, incorporating the DM to EUR conversion as an automatic 2001 crossing threshold.

Now, nothing prevents one to create new templates based on both Inflation and Currconv. For example, thinking on your template's name, I imagine one might create a DE Inflation that would go around  parameters to decide whether to return a converted value or not over a default threshold. This adds flexibility without bloating. You have some foundational addons, such as this one, and then higher level ones that take advantage of them on their own specific ways, without the need to overcomplexify thing down here.

On the granularity level, it'd be doable with optional named parameters. We could add, say, sm and em for, respectively, start_month and end_month. If the underlying template is granularized enough, the calculation would use both parameters. If it's not, it could simply ignore them. What do you think? -- alexgieg (talk) 12:13, 11 June 2008 (UTC)


 * I think what you suggest for additional granularity works for the user-side of the equation. A good method may be nested #switch, determine the year and then if a month is given use the monthly as opposed to annual index. As for currency conversions, it makes sense that this template just returns multiplication factors from the Index data (so not converting), auto-conversion happening on other templates. However, the documentation has to make clear what this template actually does and how to use it, with respect to that situation. At the moment, it does not explain what consequences the DM->Euro switch have for the user (they have to add a conversion factor by other means). I know it produces like-for-like, not DM to EUR, but the documentations does not explain that.--Nilfanion (talk) 12:56, 11 June 2008 (UTC)


 * Good reminder. I'll add that information to the documentation later today. -- alexgieg (talk) 13:53, 11 June 2008 (UTC)

Printing the "current" year?
Is there anyway that the template could optionally output something like in 200n after the number, with the most recent year there is data being output when there's not a second year provided. That way when the template is updated with a new year's worth of data, the dollar amount would have a specific date, like "N,NNN in 2007", rather than something more nebulous like "N,NNN today"? — Bellhalla (talk) 12:19, 20 June 2008 (UTC)


 * Not a bad idea. It could be a Formatprice option. I'll try adding it in a few days. -- alexgieg (talk) 14:00, 20 June 2008 (UTC)


 * Any luck on this? — Bellhalla (talk) 04:05, 23 July 2008 (UTC)


 * This should not be in Formatprice. That template does not deal in different currencies or different years. It should go in Inflation, or maybe in a variant, such as . Most importantly it should be easy to update everything in one go. So if Inflation is updated by a maintainer for a new year for some currency, the maintainer will almost automatically also update the year that is shown by the option requested here. --Hops Splurt (talk) 15:20, 21 December 2011 (UTC)


 * I could use this feature too. Currently I feel obligated to use 2008 as the end date because if I leave it blank, the reader doesn't know how recent the calculation really is.  Along the same lines, a way to call Inflation and return only the most recent year would let me put that in the header of a table such as this one.--Dbratland (talk) 15:46, 7 May 2009 (UTC)


 * This would be a useful function. I would prefer it (like Dbratland above) as a simple year string, so it can be used in situations where no specific amount is shown. Example: "In the table below, prices are given in dollars.", which would print as "In the table below, prices are given in 2011 dollars." Note: "year=" will make the named parameter "year" defined, causing the template to print only the year. Bit clumsy syntax, I confess. This could be hidden with an  template, which simply calls Inflation with the "year=" parameter. Also note that in general terms updates of the "current" year will not happen for all countries at the same time, so a Country parameter will be necessary. --Hops Splurt (talk) 15:20, 21 December 2011 (UTC)


 * I'll consider developing this, but your expression "year dollars" without explaining the method of inflation is a naïve approach to inflation that could get your use of the template removed for OR. Fifelfoo (talk) 22:04, 21 December 2011 (UTC)

Update 2008
The preliminary inflation rate for € in 2007 is 2,6 %Karsten11 (talk) 15:03, 31 December 2008 (UTC)

Efficiency
The calculation could be made more efficient if it stored a cumulated inflation factor, i.e. inflation since the startyear. To calculate inflation from year A to year B, you'd just divide the cumulated inflation from startyear to B by the cumulated inflation from startyear to A. For the UK template in particular, it would bring it from evaluating 743  functions down to two   functions. Only downside is that updating the data is not quite as straight forward, but since that only happens once a year ... Amalthea 13:39, 20 April 2009 (UTC)


 * Note that big es aren't that efficient either. J IM ptalk·cont 00:08, 15 August 2009 (UTC)
 * Here's a thought: instead of currency subtemplates have year subtemplates. Each year subtemplate would have a  (such a  would be smaller & have the most common currencies up the top to enhance performance with respect to template limits).  You go from the start-year subtemplate to the end-year subtemplate dividing one value by the other & then multiplying by the input vlaue.  It should be more efficient and in the long run ... probably a pretty long long run judging by the size of some of those existent subtemplates ... might save time by having only one subtemplate to create per year (as opposed to having several to update). J IM ptalk·cont 00:27, 15 August 2009 (UTC)

Deinflation option would be useful
Since someone offered in the "Limitations" section of, I would like to see a deinflation option added. The reason is that it is sometimes necessary to compare the specific price in an article, for example about a new product, with general price from an earlier period. "This convertable is more affordable than models produced in the 1960s." That is, the reader may not know or care about some particular, specific model from 40 years ago, but they may be interested in mapping the current product information back to (unidentified, unknowable) products that they recognize. (Maybe not a 1960s automobile at all, but a 1960s boat, house, salary, etc.) Thoughts? Piano non troppo (talk) 02:56, 20 August 2009 (UTC)

end_year
I'm ok with this defaulting to "recently", but when values are actually calculated, does this evaluate as Currentyear so that it updates on the fly, or does it depend on whether this template is subst'd? It obviously saves a great deal of effort if we don't need to update end_year manually. Or have I missed something? Rodhull andemu  23:48, 17 October 2010 (UTC)

George Washington
I was trying to calculate inflation for $8,000 received from George Washington's 1799 will, but discovered that I had to use the year 1800. I then noticed inflation from 1800 and 1801 resulted in less money in today's terms than in 1802. Shouldn't there be more money the older you go back in time due to inflation? Here is a short table to show you what I mean: Why is 1800 ($102,211.76) and 1801 ($104,256) less than 1802 ($121,227.91)?-- Uzma Gamal (talk) 10:06, 17 November 2010 (UTC)
 * 1799: $0
 * 1800: $0
 * 1801: $0
 * 1802: $0
 * 1803: $0
 * 1804: $0
 * 1805: $0
 * 1806: $0
 * Deflation in US in 1799-1802, no ? Why do you assume a permanent inflation each year ? verdy_p (talk) 07:27, 27 November 2010 (UTC)
 * Why are you using consumer price inflation for a massive capital sum such as $8,000 in 1799 money? Fifelfoo (talk) 23:55, 6 January 2011 (UTC)

Reichsmarks to euros?
I'd like to use this template in the article for the 1927 silent film Metropolis. Specifically, I'd like to have this figure's current value in euros:

The most expensive silent film ever made, it cost approximately 5 million Reichsmark.

But it's not straightforward. Any suggestions? — Athelwulf [T]/[C] 00:01, 19 December 2010 (UTC)


 * You can't use this template to inflate a capital expenditure such as five million Reichsmark in 1927 dollars. This template only inflates using consumer price indexes.  My advice is to find a capital values inflation series, or a GDP value inflation series.  Either of these would represent either the relative captial price of producing Metropolis in 1927 in terms of today's access to capital in Germany OR the total fraction of the German economy required to produce the film in today's terms.Fifelfoo (talk) 23:57, 6 January 2011 (UTC)


 * That is true, but there is a different question, and that is currency conversion. One might want to give an inflation adjusted value in a different currency, slightly complicated as exchange rates change faster than inflation rates.  As for the question above, and consider for a case where consumer price is applicable, how do you convert across the Euro conversion? Gah4 (talk) 02:38, 3 November 2016 (UTC)


 * In 1999 the DM was converted to euros at a conversion rate of DM 1.95583 to 1 euro. The inflation series should be independent of the currency (because it's a normalized index), so if you are inflating a DM amount to a euro amount then you need to alter it by the above conversion factor. Betty Logan (talk) 03:16, 3 November 2016 (UTC)

Inflation/UK/dataset cites incorrect datasource
Inflation/UK/dataset cites a US dataset incorrectly in its documentation. Fifelfoo (talk) 00:53, 11 January 2011 (UTC)

RFC: correlation between Inflation/UK/dataset and MW UK RPI dataset
Can the template author explain how Template:Inflation/UK/dataset's figures relate to the MW figures it is based on at MW UK RPI dataset? If they could document this relationship, I could clone the RPI long series for long series Average Nominal, Average Real, GDP sets, etc. Fifelfoo (talk) 01:01, 11 January 2011 (UTC)

CPI notice
Since the documentation has been updated noting not to use this template for things other than consumer goods, I have a request/question. Can we add a parameter to this template to specify which inflationary adjustment calculation method is used and then add the necessary datasets to make that happen? I've found the concept of having constantly updating inflation adjustments via template to be incredibly useful, but if this template is wrong for certain uses, can we update it so we can make it work for other applications?  Imzadi  1979   →  10:16, 24 January 2011 (UTC)


 * If the template author could answer the question in the section immediately above, other economically trained editors could produce a variety of other measures. Fifelfoo (talk) 06:23, 13 February 2011 (UTC)


 * I am working on this currently. Fifelfoo (talk) 00:44, 17 October 2011 (UTC)

Capital expenses, government expenses etc.

 * This template is not valid for "Capital expenses, government expenses, or the personal wealth and expenditure of the rich". So... is there a template that is valid for these figures? See for example "Blackburn... persuaded the legislature to apply a $100,000 allocation from the U.S. Congress" in Luke P. Blackburn. – Peacock.Lane 01:51, 4 March 2011 (UTC)


 * I have repeatedly requested that the template author contact me so I can write such an addition to this template. No such template exists right now. Fifelfoo (talk) 03:01, 4 March 2011 (UTC)
 * Template author inactive since October of last year. Given the relevant data, creation of such a template or templates might not be too challenging. – Peacock.Lane 03:26, 4 March 2011 (UTC)
 * The template's data store doesn't "gel" with base year indicies available online, at least, for UK data. Measuring Worth contains a series of time series indexes organised by different attitudes to the meaning of money over time.  The data set used in Inflation does not correspond to any of the MW data—the template author converted other people's data prior to use into an arcane and undocumented format.  And it isn't some other "base year 100" from the look of it. Fifelfoo (talk) 04:05, 4 March 2011 (UTC)
 * The more I think about it, the more I question whether the template author's assertion that CPI cannot/should not be used as an inflation index for government expenditures etc. is a worthwhile one. Surely, in some technical contexts the distinction between the value of a $100,000 gov't expenditure in 1881 expressed via CPi as opposed to some other index may be valid. However, encyclopedia readers are accustomed to CPI info if they are accustomed to anything at all, and the CPI is the "default mental image" that is most intuitively accessible to the lay reader. So... although the implementation may be dodgy (as you suggest), I'm not sure that using CPI is inappropriate for wider contexts...– Peacock.Lane 05:25, 4 March 2011 (UTC)
 * Except 1800$100,000 is not a consumer bundle expenditure, it is a capital expenditure, and ought to be inflated against capital measures. Similarly with Megaprojects that are shares of GDP.  Fifelfoo (talk) 05:44, 4 March 2011 (UTC)
 * As I said, I believe this distinction is lost on the lay reader. However, as i also said, given the appropriate data a fix should not be intimidating. – Peacock.Lane 05:58, 4 March 2011 (UTC)

Whether one wishes to use CPI or some other price index depends on the question one is asking. Fifelfoo is probably right that using CPI to compare the expenditures of the rich across time is fraught with problems, since CPI is based on a consumption basket of a "typical" household, rather than a "wealthy" household (in historical terms an added complication is that a 19th century "wealthy" household was in fact poorer than a "poor" household today in absolute terms, save perhaps the top .00001% of population). This doesn't make this template invalid, it just means it should be used with extreme caution. I was a little worried about which price series was used for the pre-industrial revolution but it seems that it was from the measuringworth.com website, which as far as I can tell uses the Bowley-Wood price series, which, while they do have some (understandable) problems, are pretty much "the best there is".Volunteer Marek (talk) 00:29, 23 March 2011 (UTC)

I'm still a little lost as to why one can't use CPI for government purchases - it's done all the time.Volunteer Marek (talk) 00:31, 23 March 2011 (UTC)


 * Government acquisitions are either labour or capital or macro-economic—I'm not seeing "consumption" expenditures. Unless we're talking about the economic impact of travel subsidy mechanisms for staff below senior executive service, CPI isn't particularly relevant.  Additionally, when the government indirectly purchases "CPI" bundle goods, through welfare, makework, industry subsidy these are generally considered either as: GDP supplements to growth in a Keynsian context, Direct Capital Investment when discussing the impact on a Firm, or Wages when discussing the total social wage of the unemployed.  I'm having difficulty seeing when it would be appropriate to use CPI to discuss government expenditure at all?  When we discuss "What was welfare worth" we either use a wages margin series base (minimum) and marginal ("skilled") or we talk about the actual consumption bundle, where CPI inflation would be useful.  But again, that's not exactly Government expenditure, that's how many sausages poor relief would buy you.  Care to help me out on the point you're making; because I can't see the Government confronting the economy as a consumer bundle purchaser, but as a Macroeconomic intervener? Fifelfoo (talk) 00:47, 23 March 2011 (UTC)


 * There are measures of government "consumption" out there and they're widely used in empirical work. For example in the Barro&Lee data set. Defense spending is mostly counted in not-consumption part. Welfare, makework and industry subsidiies are transfer payments and as such do not count in GDP (except for the cost of implementing these things). In many applications it's probably better to use the GDP deflator to compare government expenditures over time. But yes, if you want to know "how many consumption bundles" did the government purchase and compare that over time then CPI is the appropriate index. On the other hand the Bureau of Economic Analysis uses its own government specific price index I believe (see here - table 3.15.4).Volunteer Marek (talk) 02:46, 23 March 2011 (UTC)
 * I just checked the correlation coefficient between BEA's price index for government expenditures (table 3.15.4) and its general CPI index. It's 0.99418. So if someone uses the CPI instead of this other index, they're not gonna be too far of in any meaningful sense.Volunteer Marek (talk) 02:56, 23 March 2011 (UTC)
 * Based on the fact that both series probably have a unit root and that this can account for the high correlation, I also first-differenced the series and looked at the correlation of the first differences. This was .765 which is still very high, esp. since we're now talking differences.Volunteer Marek (talk) 03:03, 23 March 2011 (UTC)
 * Thanks Marek! I find it bizarre and counter intuitive that the BEA correlates strongly with the CPI!  Obviously even military spending is predominantly consumption bundle related (soldiers' non-paid wage component, etc.).  Or perhaps within the US the rate of profit/productivity for CPI / BEA bundles are highly equivalent due to other factors.  Does the BEA have a series depth back to 1800?  Fifelfoo (talk) 02:22, 5 October 2011 (UTC)


 * Why can't the qualifier be built into either the template, or (probably more accurately), uses of the template? "in 2010 CPI dollars," or if this has some kind of designation, "M8" with link, for example. Assuming there is such a thing. (Yes, I'm talking about money supply, not the currency, but maybe there is an equivalent). Student7 (talk) 20:06, 12 October 2011 (UTC)
 * Because you can't convert time-as-capital-expense money into time-as-labour-consumption money. The problem isn't footnoting this correctly, most of our notes specify the data's methodology, but that User X thinks this template allows simple time conversion of any monetary sum, regardless of a market or capitalist economy existing in those products, regardless of the nature of money (its contingency, the capacity for feudal states to resume it such as the seizure of the goldsmith's reserves in the UK).  The problem isn't the template, but the use made of the template of Wikipedia.  Fifelfoo (talk) 00:10, 13 October 2011 (UTC)


 * Not to put too fine a point on it, this means (for the US) that $16 in capital bought one ounce of gold from year x to 1933 (or whenever). This capital figure does not allow for consumer depression or inflation when the US was forced to sell or buy gold to "maintain" the dollar. A consumer index necessarily ignores this "fixed" price which the template presumably covers. Is this correct? Student7 (talk) 19:25, 16 October 2011 (UTC)
 * The reference commodity isn't gold—the idea is that fiat (or goldbacked) currency constantly fluctuates in value, but more importantly, the volume of social production fluctuates in value. For CPI figures, the reference commodity is a bundle of "consumer goods" depending on what the statistical bureau determines is an appropriate bundle.  In the Australian case this is housing (a complex calculation), milk, meat, bread, electricity, gas, etc.  As the standard of consumption changes, the statistical authority has to revise the CPI reference bundle.  The current Capital measure (UKNGDPPC) is for nominal (ie: 1933 in 1933 Pounds, 2007 in 2007 Pounds) Gross Domestic Product (ie: output) per capita (ie: divided by a productivity measure).  Because Nominal GDP is in nominal, not in benchmarked, dollars, it allows year-to-year comparisons of dollar volumes, indicating to a 2010 reader how much national output would be required.  At this level, government intervention into the price of money isn't as important as long term changes in productivity and volume of output.  You might want to read GDP deflator which discusses another way to view private capital costs over a long term. Fifelfoo (talk) 00:43, 17 October 2011 (UTC)

Output
Just discovered this. Incredible!

I would like to ask for something (kind of touched on earlier, above) for output. I would like to see the output for $ as "$n1 in year ($converted n1 in 2008)" or something that defaults to a complete explanation. The default could be overridden, for say, tables. Student7 (talk) 19:57, 24 April 2011 (UTC)

Beta announcement: UK National Gross Domestic Product per capita following Measuring Worth
Dear editors, I'd like to announce a beta phase for the UK National Gross Domestic Product per capita inflation template: UKNGDPPC. For example: }} you could use, instead of you could use  and instead of  you could use. It's no big deal when the number of pennies (or farthings for that matter) is a multiple of three but if not you get either 3 or 6 recurring in the decimal, which is too much bother. If it would be worthwhile, the template could be reworked to accept £sd input with the pounds shilling and pence separated by hyphens (or slashes). J IM ptalk·cont 16:38, 21 March 2013 (UTC)
 * Considering the per person productivity of a society as a key indicator of the economic stress required to produce mega projects, the 1970 British megaproject of repairing London after the attack of giant atomic monster cats which cost £1000 billion would put a stress on 2010 British society similar to £ billion.


 * Example:
 * Example:

All the best: Rich Farmbrough, 16:10, 14 December 2015 (UTC).

Request for feedback on my usage of this template
Greetings!

I recently added this template to three articles, but before I go much further, I'd like to get some feedback from other editors on whether or not I'm heading in the right direction. Before I edited them, the articles contained (relatively) modern equivalents of past US dollar amounts that have been "hardcoded" into them. The problem with that method is that those equivalents will become less meaningful over time and may need to be updated periodically. What I've tried to do is insert templated text so that, going forward, the equivalent amounts will automatically stay current. My hope is that this will make those amounts more relevant to readers while requiring less article maintenance by editors.

The three articles in question are:
 * 1) Walter Hunt (diff)
 * 2) Treaty of Fort St. Stephens (diff)
 * 3) Amadeo Giannini (diff)

Of course, if the consensus is that my changes to these articles is inappropriate, I will gladly undo any damage I may have done. Thank you in advance for any comments or suggestions you care to make (please leave them here; I'll keep an eye on this talk page for a while). Cheers! &#10146; Bgpaulus (WORDS &amp; DEEDS)  22:41, 1 August 2012 (UTC)


 * In Walter Hunt you replaced a "reliably sourced" inflation measure to the extent that we trust Wired's capacity to measure worth over time correctly, with a CPI inflation figure for a capital good. Not a good inflation.  CPI does not measure changes in prices of capital goods. Fifelfoo (talk) 23:34, 1 August 2012 (UTC)
 * Treaty of Fort St. Stephens represents the actions between two states; which is not measurable in US CPI—at best, if this should be measured at all, this should probably be GDP% or GDP/capita. Not a good inflation. Fifelfoo (talk) 23:38, 1 August 2012 (UTC)
 * Amadeo Giannini again has a capital good inflation measured in CPI—not at all appropriate.
 * Try reading Measuring economic worth over time and then perhaps measuring worth's website. Fifelfoo (talk) 23:38, 1 August 2012 (UTC)
 * Interesting discussion Fifelfoo, question though, measuring worth's website? Where is that, first result on google? Marketdiamond (talk) 11:55, 8 October 2012 (UTC)
 * Yes, good stuff, I learned something new today, and the day is so young... The site is www.measuringworth.com.  Fifelfoo, as to whether Wired's inflation measure is "reliably sourced" "to the extent that we trust Wired's capacity to measure worth over time correctly", I'd say "don't count on it" – until today, this computer geek, for one, would have gotten it wrong.  Then again (asking rhetorically), how many journalists or other "reliable sources" actually understand the information they parrot back to the masses? But enough of that, back to my happy place...  Groll &tau;ech  ( talk ) 13:59, 28 November 2012 (UTC)

Proposal to allow commas or show errors
I have rewritten the /sandbox version to allow commas in the amount, and show error messages for specific problems in the year range or invalid amounts. Parameter "fmt=c" will put commas in the result, or "fmt=eq" will show "equivalent" phrase (default: fmt=raw). For example:
 * {&#123;inflation/sandbox|US|25,000|1910}} &rarr;
 * {&#123;inflation/sandbox|DE|1,000,000|1957|1978}} &rarr;
 * {&#123;inflation/sandbox|DE|1,000,000|1957|1978| fmt=c}} &rarr;
 * {&#123;inflation/sandbox|US|1,000|1957|1990 | fmt=eq}} &rarr;
 * {&#123;inflation/sandbox|UK|1,000|1957|1990| fmt=eq|cursign=£}} &rarr;
 * {&#123;inflation/sandbox|UK|£67|1897}} &rarr;
 * {&#123;inflation/sandbox|UK|67|1897}} &rarr;
 * {&#123;inflation/sandbox|UK|67|1066}} &rarr;
 * {&#123;inflation/sandbox|UN|67|1266}} &rarr;

I think the rewrite is working fine, and only increases the expansion depth by 1 level (as 12) to show commas, because each error condition is tested outside the prior template markup and does not nest the depth of calculations. Prior to 2008, a template with error-message validations would expand the size of a formatted page, but since January 2008, the parser includes just the true conditions of if-structures and omits any unused error-message markup. If there are no other concerns, then I will install the new version in a few days. UPDATE: The new version will also allow option "fmt=eq" as in examples above. -Wikid77 (talk) 12:40, 9 November 2012, 10:43, 12 January 2013 (UTC)
 * Just curious if you know the cause of the "unrecognized punctuation" bit? Groll &tau;ech  ( talk ) 12:05, 28 November 2012 (UTC)
 * It's trying to use as the argument in an expression (specifically, , but the template doesn't exist ( doesn't exist either, but I think that there is sufficient error trapping for that). Rather than throwing potentially non-existent templates into expressions and hoping that   will catch them, it might be better to use code like  . -- Red rose64 (talk) 12:57, 28 November 2012 (UTC)


 * DONE - Upgraded for commas, fmt=c and fmt=eq: I have typically avoided #ifexist because it has been counted as an "expensive function" with limit of 500 per page, which would limit price lists (or tables) to 500 entries total. Perhaps in another upgrade to the template, then checks with #ifexist could be added to detect other data problems. For now, I have simply upgraded today for allowing commas, checking year limits, new option "fmt=c" to show commas, and new option "fmt=eq" to show typical "equivalent" phrase. -Wikid77 (talk) 10:43, 12 January 2013 (UTC)

Updating the inflation formula for 2013?
Hi all, great work here! I was wondering when these type formulas: $ would be updated with the 2012 inflation data (to reflect current year 2013 values). Is there some government report we are waiting on. . . or if its already being worked on by wikipedians then you have my thanks!  Market St.⧏  ⧐ Diamond Way  20:32, 2 January 2013 (UTC)
 * 2012 data normally becomes available in late 2013, and only stabilises around 2017 or so. Fifelfoo (talk) 04:51, 9 January 2013 (UTC)
 * Thanks for the clarification, so I guess I get that old econ joke now--by the time you know what the inflation was . . . its way too late, I knew it wasn't instantaneous but kind of shocked it takes almost a year just to get the preliminary data out.   Market St.⧏  ⧐ Diamond Way   11:02, 10 January 2013 (UTC)

Help with errors
I am now seeing error messages in Ely and Littleport riots of 1816. I do not know what is wrong or how to fix it. Any help would be appreciated. Joja lozzo  18:31, 12 January 2013 (UTC)
 * should have fixed it. Until June 2009 I was paid to find and fix stuff like this. -- Red rose64 (talk) 20:29, 12 January 2013 (UTC)

Amounts less than ₤1
Template:Inflation outputs an ugly error message if the currency amount is less than ₤1.00. This is unfortunate, because one pound has historically been considered a large amount compared to prices for most everyday personal transactions, as described in the documentation of the template.

The workarounds below adapt suggestions given on the Template:Inflation documentation page and its talk page for manually converting between currencies. The suggestions here can be used to directly enter amounts in shillings or old pence, for amounts both less than and greater than one pound. — Preceding unsigned comment added by Monomoit (talk • contribs) 22:37, 12 January 2013
 * Which page are you seeing a problem on? -- Red rose64 (talk) 22:42, 12 January 2013 (UTC)
 * I've found it; it's London Necropolis railway station. All you needed to do was insert a zero before the decimal point, . -- Red rose64 (talk) 22:47, 12 January 2013 (UTC)
 * Thanks for your quick attention. The first thing I tried was inserting the zero, but I don't understand why this gave an error message complaining about a leading zero. The workarounds below can be useful for an author wishing to convert values based on shillings or pence rather than pounds.Monomoit (talk) 02:39, 13 January 2013 (UTC)
 * I fixed the problem with leading zeroes at ; if you had tried before then, it would have thrown an error. -- Red rose64 (talk) 11:05, 13 January 2013 (UTC)

Whole shilling amounts
As an example, one author wanted to display the equivalent, in today's money, of ten shillings in 1854. In this workaround, the amount can be entered directly as, which the template interprets as "10 pounds", 20 times the correct value. To compensate for that interpretation, the  operator is used to divide the result by the same factor. Remember that  is simply the number of shillings in one pound. (The  option of   indicates the number of decimal places in the final result.)

Example: £0

gives:

£0

Shillings and Pence
The previous example can be adapted to any number of whole shillings. Also, multiples of 3 d. can be entered as a decimal fraction of a whole shilling. For example, 30 s. can be entered as, and 2 s. 6 d. can be entered as.

Generally, an amount in shillings and pence needs to be converted to the total number of pence, and the factor  used as the divisor. Ether of the following will correctly handle the amount 2 s. 6 d..

£0 £0

gives:

£0

£0

Monomoit (talk) 22:37, 12 January 2013 (UTC)

Alternatively
You can put the fractions inside so as to avoid having to use the #expr.

£0 £0 £0 £0

give:

£0 £0 £0 £0

J IM ptalk·cont 11:08, 22 March 2013 (UTC)

'cursign' option not working?
The 'cursign' option doesn't appear to be working, at least in this instance:



I can add the $ manually, but should I be concerned about that option becoming active again at some point? Praemonitus (talk) 20:23, 20 April 2013 (UTC)
 * According to the documentation, you need to set eq to get the "equivalent to" phrase:
 * -- Red rose64 (talk) 22:12, 20 April 2013 (UTC)
 * -- Red rose64 (talk) 22:12, 20 April 2013 (UTC)


 * Are you saying that is the only way it will work properly? Praemonitus (talk) 23:25, 20 April 2013 (UTC)
 * The cursign parameter sets the currency sign used in the text "equivalent to $". That text only appears when eq is set. -- Red rose64 (talk) 08:34, 21 April 2013 (UTC)
 * I took the liberty of updating the documentation accordingly. Thank you. Praemonitus (talk) 15:02, 21 April 2013 (UTC)

Is there any possibility that this feature could be extended to display the proper year, and not default to 2013? For example, displays  however that dataset only goes up to 2011. It would vastly simplify things in articles if it would display the appropriate year based on the dataset used.  Imzadi 1979  →   06:39, 11 September 2013 (UTC)

Updating the UK figures
The UK figures are out of date. Rather than overwrite them with new figures I've created a new currency called TEST that can be used e.g., and a couple of testcases on Inflation/testcases. I've downloaded a new dataset from measuringworth.com; there are differences with the current UK/dataset, but according to measuringworth.com this to be expected and the new data is more accurate. (There also appears to be an error at the end of the current data, where 2009 is less than 2008)?

Could someone else please check over what I have done, before I copy Inflation/TEST/dataset into Inflation/UK/dataset [just fixing the documentation] and update the year in Inflation-fn? Edgepedia (talk) 15:23, 28 July 2013 (UTC)


 * I'm going to be bold and update the data. This will change to-date calculations by about 10 per cent and other uses slightly. As this will involve the update to two pages and the template could be used between these (or my laptop or internet link could go down), I will update in the following sequence:


 * 1) Inflation-fn: The UK portion changed to UK Inflation figures are being updated. Please reload this page to fix the problem.
 * 2) Inflation/UK/dataset: copied from Inflation/TEST/dataset
 * 3) Check the results on Inflation/testcases
 * 4) Inflation-fn: The UK portion changed to UK CPI inflation numbers based on data available from Gregory Clark (2013), "What Were the British Earnings and Prices Then? (New Series)" MeasuringWorth.
 * 5) Check the results on Inflation/testcases

When I've done all that I'll be back. Edgepedia (talk) 04:51, 30 July 2013 (UTC) ✅. I've checked a few transclusions and it all looks well to me. Edgepedia (talk) 05:02, 30 July 2013 (UTC)

I've just created the template that gives the current year for the relavant inflation figures. For example,

gives

A pre-decimal penny was worth in 1836 about the same as p in.

Of course this needs to be manually updated when the figures are updated. Thoughts? Edgepedia (talk) 18:17, 7 October 2013 (UTC)


 * Thank you! This will greatly simplify article maintenance since as the templates are updated in concert, the articles will automatically indicate the year being used.  Imzadi 1979  →   19:28, 7 October 2013 (UTC)
 * Thank you from me too - this achieves what I was attempting to do with at Newcastle and North Shields Railway. On your talk page you wonder about people complaining figures are out of date. I think the answer to this is to either include (probably as part of the footnote) a few words about how inflation figures are circa 1 year delayed from real time, and/or link to a longer explanation somewhere. If not in the footnote maybe it would be possible to have this as a tooltip? Thryduulf (talk) 21:25, 7 October 2013 (UTC)

Significant figures
Have you considered adding support for a given number of significant digits? The "r=digit" parameter is somewhat inadequate, since presupposes that the user knows how many digits the final number will have, which is inherently flawed since inflation will change the final number continually over time. --Doradus (talk) 16:29, 20 December 2013 (UTC)
 * Agreed, inflation is an inexact science, so saying that $1,000,000 is now $2,132,563 (7sf) is ridiculous. ed g2s &bull; talk 12:16, 26 March 2015 (UTC)


 * But significant figures are also an inexact science, at least if you round to integers. Yes 7sf is ridiculous, but if you have r=-5 (2sf for the values shown), and after more inflation you then have three, it isn't so bad. If we get to the point of runaway inflation, keeping Wikipedia updated will be one thing I won't be worrying about. Gah4 (talk) 00:42, 2 November 2016 (UTC)


 * I didn't try it, but using  you could compute the number if digits in a value, then convert the the r= value needed.  Assuming templates nest appropriately to do that.  Gah4 (talk) 00:53, 2 November 2016 (UTC)

AU does not work
Does not work. Why? Nick Beeson (talk) 01:20, 1 February 2014 (UTC)
 * Fixed it.[//en.wikipedia.org/w/index.php?title=Template:Inflation/AU/dataset&diff=prev&oldid=593399768] There was no default value to the switch statement, which meant it returned blank and this was trapped as an error. Did it ever work? Edgepedia (talk) 07:10, 1 February 2014 (UTC)

Indian rupee
About a year ago I added the Indian rupee. I have to admit, though, whilst I get how the template works, I'm a bit mystified as to where the data is coming from. The numbers I used to create the Indian rupee conversion were borrowed from someone who was working on INRConvert. I hope they were right but it would be nice to check. Another problem is that the range is only from 1953 to 2013. It's now one year on and time to add 2014. Also it might be nice to add values for earlier years.

I wonder whether anyone would feel up to checking these numbers and/or adding more. If not, I wonder whether anyone would be able to point me in the right direction as to where we're normally going to find this data. For example, how about this website which gives an average inflation rate of 10.92% in 2013? Would this make sense given that data?

Jimp 10:46, 7 April 2014 (UTC)

Very good!
This is extremely useful, I wish I had known about it earlier. Any suggestions on how to find articles that I created in the past that might take use of this? Maury Markowitz (talk) 15:29, 6 May 2014 (UTC)

Any way to automatically round to cents when cents are input (or when the output is less than 1)?
Before I added the rounding parameter, U.S. Route 67 in Iowa claimed 50 cents in 2003 was $1 in 2014. --NE2 06:20, 13 June 2014 (UTC)

Large numbers question
If I put "$10 billion" in the raw text, what's the proper way to get the template to give me:

$77 billion in 2014

It doesn't seem this is possible? Maury Markowitz (talk) 18:15, 18 June 2014 (UTC)

Two questions: First, you need an index appropriate for large numbers. Second, the conversion is linear, so just convert 10 with r=0. Gah4 (talk) 22:45, 23 November 2016 (UTC)

$10 billion in 1975 was worth $ billion in 2014.

$10 billion in 1975 was worth $ billion in 2014. Gah4 (talk) 22:53, 23 November 2016 (UTC)
 * Actually, I suggest the following:
 * to give:
 * $ in
 * Please note that the inflation-year template gives the proper year and is updated as the data sets are updated each year. By wrapping the inflation template in format price and using the full amount, it will round off the result for you neatly.  Imzadi 1979  →   23:22, 23 November 2016 (UTC)
 * Please note that the inflation-year template gives the proper year and is updated as the data sets are updated each year. By wrapping the inflation template in format price and using the full amount, it will round off the result for you neatly.  Imzadi 1979  →   23:22, 23 November 2016 (UTC)

How to remove "equivalent to"
Hi, is there a way to use this template – – to say "$12,000 in 2014," instead of "equivalent to $12,000 in 2014'? There's a particular article where I'd like to use the template for several figures, but it looks cluttery to keep saying "equivalent to." SlimVirgin (talk) 16:22, 24 July 2014 (UTC)
 * Yes, just leave off the eq - You need to add your own currency symbol though. -- Red rose64 (talk) 16:37, 24 July 2014 (UTC)
 * Thanks. Leaving that off gives me "12000," so I'd have to format it manually and add the year, and presumably keep on changing it manually. I was wondering if there was a way to have the same functionality as the template, but without the words "equivalent to." SlimVirgin (talk) 16:41, 24 July 2014 (UTC)
 * If you want commas, use c - . It's all in the template's documentation. -- Red rose64 (talk) 18:55, 24 July 2014 (UTC)


 * Do you think anyone would mind if I were to (try to) remove "equivalent to" from the template, so that fmt=eq produced "$12,000 in 2014"? That would be the easiest way round this; the words ""equivalent to" are redundant. SlimVirgin (talk) 19:27, 24 July 2014 (UTC)
 * I just read this now, wanting the same thing. An earlier discussion developed the template Template:Inflation-year, which can be used after the inflation template to put in the inflation year automatically and update automatically. ɱ  (talk) · vbm  · coi) 19:38, 23 June 2016 (UTC)
 * thank you, that's good to know. This is a nice delayed response. :) SarahSV (talk) 20:33, 23 June 2016 (UTC)

suggestions for 1700s?
At Sally Hemings there are several dollar figures that predate 1800. Do you have any conversion suggstions?--TonyTheTiger (T / C / WP:FOUR / WP:CHICAGO / WP:WAWARD) 22:11, 27 August 2014 (UTC)
 * ,, , , , , and , you comprise the most active editors of this template and its talk page. Can someone respond to my query.--TonyTheTiger (T / C / WP:FOUR / WP:CHICAGO / WP:WAWARD) 16:46, 31 August 2014 (UTC)
 * Tony, it's not easy for that historical period, particularly for the pre-independence US (where cash and manufactured goods were often limited, skewing values of goods and currencies etc.) Measuring Worth will give you some options, but care will definitely be needed. One option would be to give some alternative contemporary (1700s) figures, but you'd want to be careful not to be carrying out OR in the process. Hchc2009 (talk) 17:02, 31 August 2014 (UTC)
 * Don't. Converting prices over time is a matter of original research.  Let some historian elsewhere describe the meaning of cash values in time to different people and use that.  And this doesn't mean "go read books on other topics until you find an equivalent cash value," it means wait until someone one your subject publishes an equivalent, "He bought it for half a cent, this being the price of a beer in that region at the time." Fifelfoo (talk)

{inflation-year} - no mention in documentation, uses needed in the wild
Since mid-2013 (see further up this page) we have had the to note when the inflation figures are accurate to, but there is still no mention of it in the documentation of this template. This is possibly why I'm still finding and fixing other statements in the wild, e.g.. I don't have the time to sort this at the moment (and I'm not the best at writing that sort of thing either), but it is something that should be mentioned. Thryduulf (talk) 23:18, 3 January 2015 (UTC)
 * I've just updated the only use of 2024 I can find in this documentation, but there are still many incorrect uses in the wild that should be using . Thryduulf (talk) 14:13, 15 April 2015 (UTC)

List of transport megaprojects
I've been looking around for a way of including inflation adjusted values in the table at List of transport megaprojects, but so far have not been able to find a reliable way of doing it without resorting to original research. This template would seem to be a model for how to do it, but if I understand there is still somewhat of a consensus that you cannot use it for capital projects such as transport megaprojects? Any opinions on the suitability or lack thereof for using this template on that page, and any possible alternatives? Thanks, Peregrine981 (talk) 20:39, 21 May 2015 (UTC)
 * There is a construction index issued by RIBA. All the best: Rich Farmbrough, 16:19, 14 December 2015 (UTC).

Inconsistency in "latest year" of data
At the moment, when the  parameter is used, the output assumes that the data sets are complete up to the current year. For example:

generates: "equivalent to £190,000 in 2015".

However, the UK dataset only goes up to 2014 and others end earlier than this. Could the template be modified to use inflation-year instead of 2024 ? We would then get the more accurate "equivalent to £190,000 in 2014". — Preceding unsigned comment added by DavidCane (talk • contribs) 01:30, 28 May 2015

Significant figures
Right now the template has an option to round off the calculated figure to a certain number of decimal places. There should be a similar option to do it to a certain number of significant figures.BaronBifford (talk) 09:20, 4 January 2016 (UTC)

If you know the value, the number of digits should normally be close enough. Are there cases where you don't know the number well enough? Gah4 (talk) 00:37, 2 November 2016 (UTC)

Large numbers
I mostly work on historical articles where the unit of currency is in the millions or billions. I have always tried to use the inflation template to convert to today's values, like this : "$100 million ($250 million today)"

I would like to begin using fmt=eq instead of typing "today", but I cannot figure out how to do it easily with large numbers. There is the difficult to type inflation-year example, but I am not going to use that.

Maury Markowitz (talk) 02:50, 17 January 2016 (UTC)


 * What sort of large numbers are involved, by the way? The template is only suitable for staples, workers' rent, small service bills (doctor's costs, train tickets) etc., which are typically relatively small sums of money. Hchc2009 (talk) 10:42, 17 January 2016 (UTC)


 * . . I read somewhere on WP that the inflation converter was only for very small sums as you mention. Where did I read that? Lately I've seen it used a lot in movie articles to compare the gross of a movie in 1939 or such to what it would be in today's dollars. Ping me back. Cheers!  16:19, 17 January 2016 (UTC)


 * The gross of a movie should work, as that is the sum of millions of movie tickets. One would hope that ticket prices follow consumer goods rate. But it might not be good for the cost of producing the movie. Gah4 (talk) 00:28, 2 November 2016 (UTC)


 * Have a look in the actual template (not the talk page) here - it should be near the top. It's due to the index it uses. Hchc2009 (talk) 16:22, 17 January 2016 (UTC)

"Today", "recently" should be deprecated
Per WP:RELTIME, "today" and "recently" should be deprecated. Even if "today" actually does mean today, this may not be obvious to the reader. jnestorius(talk) 13:26, 18 January 2016 (UTC)

Template error for 2016 date
I have reverted alterations to the template by. Using the 2016 date in the template generates an error message:

results in

While I appreciate that using a 2016 date in the template is redundant at present (there is no inflation data) the fact is data from this year will be added to inflation adjusted lists along with the 2016 date so that the figures are automatically updated in subsequent years. If we are are forced to enter this year's data with last year's date or without a date just so the template will work then this will be a massive inconvenience because it will need to be corrected at some point. More "helpful error messages" is not an acceptable solution. Please make the template work with the 2016 date before restoring the code. Betty Logan (talk) 01:37, 13 March 2016 (UTC)


 * As mentioned in User talk:Betty Logan, it might be possible to add logic so that when a  of the current year is requested, the template correctly calculates an inflation of 0% for the period of 2016 to 2016. However, doing this will only result in delaying the error until the year rolls around and the template needs to calculate inflation from 2016 to 2017 without any information yet available from either of these years. This particular error can only be corrected by updating the datasets with more data provided by reliable sources, or by fixing pages that attempt to use the template incorrectly. It might be inconvenient to deal with the realities of referencing incomplete or outdated datasets, and you might find that inconvenience to be unacceptable, but it is even more unacceptable to sweep the issue under the rug by providing false data under the assumption that eventually someone will update the datasets. Even if you find that assumption trivial with an index like   which usually is updated fairly frequently, the assumption breaks down on indexes like   which so far only has data through 2010. Note also MOS:RELTIME. djr13 (talk) 02:04, 13 March 2016 (UTC)
 * What is inconvenient is not being able to add data for 2016 to the encyclopedia now we are in 2016. I am not asking you to sweep the problem of out-of-date data sets under the carpet, I am asking you to not cause unavoidable problems where this is not an issue. Many of the inflation datasets are updated regularly but the 2016 data has not been published yet. It probably won't be published until later this year or even next year, but that is not a problem in itself. For instance, Inflation/US/dataset has a built-in default to accommodate the current year when data has not been published. What do you expect editors to do in the case of financial data that is released this year? Do you expect them to delay adding it to articles until the inflation index series is published? No, this is what happens in reality i.e. editors start changing the year to just get the template working, and thus corrupting the data. Forcing the current year to use a rate of 0% or to default to the previous year where data is not yet available would seem like an effective solution in regards to entering 2016 data; a year's grace is all that is needed for up-to-date data sets that just have a lag in their updates. Betty Logan (talk) 02:44, 13 March 2016 (UTC)


 * There is a potential workaround to allow use of the template in anticipation of future database updates. We could create a wrapper template which simply passes, unchanged, a given value of a  as of that stated year without pretending to calculate inflation, until it finally detects an update to . Something like . Like, I can calculate right here that as of this moment, the index   is . We could even make it default behavior, though we'd have to code one with and without eq. But even then, editors will need to think about whether the inflation statement will actually be appropriate when it does change over. djr13 (talk) 05:07, 13 March 2016 (UTC)
 * Here is another example of the problem: if you look at the Deadpool entry you will see that its inflation adjustment formula was removed earlier today to correct the problem; the problem now is that when the 2016 index is updated in the 2nd or 3rd quarter that won't be reflected in the entry in that table! When dealing with current data there will often be a lag of up to a year pending the updating of the inflation series and the template needs to accommodate that. A fancy solution is not required. If the index end_year is set to 2015, then all we need is the template to not regard the start_year set to 2016 as an error. If the data sets have been updated to 2015 chances are they will be updated to 2016 at some point when the data becomes available. If the index end_years are not updated and remain set at 2015 then they will produce errors when the start year reaches 2017 anyway. All that is is needed is a +1 or a -1 strategically positioned in the template so that errors are not produced if the start_year is just one year ahead of the index end_year. Betty Logan (talk) 06:12, 13 March 2016 (UTC)


 * FYI to all here, I have modified the error-tracking category name to make it specific to this template, as we do with other templates. – Jonesey95 (talk) 20:30, 19 September 2016 (UTC)


 * It is nice to be able to add a template when one creates an article or modifies it, but I think one can wait a few years before we actually need the inflation adjusted value. (At least at current almost zero inflation rate in many countries.)  A parameter that would not print anything until after=(year) might be nice.  Gah4 (talk) 06:45, 2 November 2016 (UTC)

Capital expenditures names are unusable
For capital expenditures, we have US-NGDPPC and UKNGDPPC (though dash and non-dash formats work). This isn't ideal. Those only mean something to people with an intimate knowledge of macroeconomics, and they aren't memorable in the slightest, so that I always have to revisit this page to copy the abbreviation. A simple USCAP and UKCAP would be far better abbreviations -- memorable, meaningful, unique, and easy to type. I propose that USCAP and UKCAP should become the new keys, and the old ones redirected to them. Does anyone else agree? SilverbackNet talk 04:07, 5 May 2016 (UTC)


 * Seconded, although I think "USLARGE" and "UKLARGE" would be even easier to understand.--Father Goose (talk) 22:24, 23 November 2016 (UTC)
 * The "NGDPPC" portion of the name refers to "nominal gross domestic product per capita", one measure for dealing with these large numbers. There are other measures that could eventually be added for various specific uses, so it's best to stick with terms based on those schemes instead of inventing "easy" ones that lack any meaning.  Imzadi 1979  →   23:25, 23 November 2016 (UTC)


 * Yes, I think if we have different names, they need to be somewhat obvious how they should be used. If you buy a large quantity of consumer goods, which index is it? The gross proceeds for a movie is the sum of millions of tickets bought by individual consumers, so it is large, but, seems to me, should follow the consumer index.  So, maybe US-CONSUMER and US-CAPITAL.  Not so hard to remember. I still wonder about things that are between consumer goods and capital goods. Gah4 (talk) 23:56, 23 November 2016 (UTC)


 * A fair point, Imzadi, although the template doesn't inform readers what index is being used for the adjustment, and generalized publications almost never explain that either, it's all just "adjusted for inflation" (...magically).
 * The naming of the parameter is less important now that I've updated the documentation to explain (approximately) when to use each. Although the parameter names are still both inconsistent and ugly.
 * A bigger problem came to light when I checked Special:WhatLinksHere/Template:Inflation. Almost all uses of the template use the "US" or "UK" (CPI-based) indexes, even when converting large/capital sums.  This is presumably a consequence of editors using the template before the GDP indexes were added, and it needs fixing.  I'll start a separate thread below to discuss this issue.--Father Goose (talk) 05:04, 24 November 2016 (UTC)

Suggestion on which to use???
Following up silverbacknet's post... I was directed here after a user suggested to use it for an NBA salary cap page... and have uses for it on hurricane pages and various other articles. But... I have no idea whether I should be using US or US-NGDPPC for each. There's no explanation of what NGDPPC means on the template page... or even a Wikipedia redirect for such. I saw some explanations here, but a clear, simple explanations on which is better for which situations (and perhaps why\how major the difference is) would be extremely appreciated. JeopardyTempest (talk) 03:13, 22 August 2016 (UTC)
 * The undifferentiated  uses the Consumer Price Index, while   uses the Nominal Gross Domestic Product per capita. The former is better for small amounts related to the price of individual goods, while the latter is better for capital projects and other large amounts.  Imzadi 1979   →   03:20, 22 August 2016 (UTC)


 * The page at http://www.measuringworth.com/uscompare/ offers some guidance on which measure you should use in which context. For salaries/income I would use US-NGPPC (GDP per capita at the page I have just linked to). This is what it has to say: "The GDP per capita is an index of the economy's average output per person and is closely correlated with the average income. It can be useful in comparing different incomes over time." Betty Logan (talk) 03:26, 22 August 2016 (UTC)


 * Ok, good stuff, and really appreciate getting replies for a change on a talk page! The question then continues onto other that I came across was the Gateway Arch page (which was already using NGDPPC).  Imzadi leads me to think it'd be NGPPC due to it's scale, while Betty I'd be more uncertain with (since it has nothing to do with income).  And, for that matter, is it of small enough value to not hit the warning about not using Inflation for capital expenditure projects??
 * I'd expect the damage caused by a storm such as Hurricane Erin (1995) would also probably fit in the same category (so NGDPPC)?
 * Whatever is said, this is probably important enough to get written into the template documentation (I'll try to do after more discussion time if I remember)? It would seem something like hurricanes being compared inconsistently could lead to somewhat false results?  Thanks again
 * JeopardyTempest (talk) 04:14, 22 August 2016 (UTC)


 * Measuringworth.com is a good starting point. The right measure to use depends on a variety of factors, including what you are trying to explain by the comparison. I'd support using GDP per capita for comparing NBA salaries and limits, sounds sensible.
 * I suspect for hurricanes, though, what you're trying to get at in your comparison is "how much of the economy did the hurricane destroy?" (e.g. if Hurricane X destroyed 10% of the state's economy in 1950, how much would that be equivalent to in 2016?), in which case NGDPPC wouldn't be ideal - I think you'd be best going for a straight forward share of GDP measure. Hchc2009 (talk) 06:31, 22 August 2016 (UTC)


 * Good to know... any idea if there is an existing template to do such?
 * Thanks, JeopardyTempest (talk) 09:05, 23 August 2016 (UTC)
 * I'm not aware of a template (but I'm no template guru!) - I tend to use the Measuringworth site and cite it from there. Hchc2009 (talk) 09:19, 23 August 2016 (UTC)
 * Would it perhaps fit as a new option to this Inflation template, or be better as a separate template do you think? If it applies to things like disasters (and large government projects?), I'd think it would be of regular usage (if people knew that it's better to use than inflation)? JeopardyTempest (talk) 21:37, 23 August 2016 (UTC)

Gauging Interest in Features
Was noticing that the template appears to lack a format for common language shortening (where for example if $750,000 is now worth $84,000,000, it would automatically display $84 million, rather than having to display the whole value, or update unit set every time it changes (or have quirky 8425 million values). It'd also turn off scientific notation issues (easy enough perhaps? just divide the exponent down after it reaches the template and send the answer back with words instead). But then I noticed the currency converter appears to have really died out as well... was there not much interest\need in the end? Only a toUSD, and it seems poorly up to date, and used on fewer than 100 pages. Been looking at template at editing some recently.  But regardless whether it is me or someone else... what priorities exist in enhancements at this point? JeopardyTempest (talk) 04:04, 22 August 2016 (UTC)
 * I wrap the output of the template in formatprice and precede it by the appropriate currency when dealing with large amounts. So for instance, from Interstate 275 (Michigan):
 * "The final cost to build the I-275 freeway was $145 million (equivalent to $ in )."
 * using the code:
 * For values that output in the thousands instead of the millions, I'd use something like:
 * to output:
 * "$145,000 (equivalent to $0 in )"
 * If I didn't, the formatprice would helpfully add the word "thousands" after the base number, where we could just have it run the full figure as is usual in print.  Imzadi 1979  →   05:42, 22 August 2016 (UTC)
 * "$145,000 (equivalent to $0 in )"
 * If I didn't, the formatprice would helpfully add the word "thousands" after the base number, where we could just have it run the full figure as is usual in print.  Imzadi 1979  →   05:42, 22 August 2016 (UTC)


 * Hot dog, that's great! And explains one of the reasons I'd stumbled across all this in the first place (wondering why   was used instead of  .  I had overlooked the formatprice wrapping the first part and stopped reading the template documentation page at the end of the heading "Very large results" instead of carrying on to the next heading "Format price" (perhaps those should be combined and formatprice should be emphasized as the better way?).  Personally still seems it'd be great to include a formatting options inside inflation itself to avoid the long string of code to do this, particularly since it seems fmt=eq has limited utility in its current form?  But very glad to have the alternative to sidestep that.
 * Thanks a lot for the response JeopardyTempest (talk) 09:02, 23 August 2016 (UTC)

Trailing zeros with cents (using r=2)
As it stands, the template drops a trailing zero in this scenario. I argue that this is a bug and that it should be fixed. Here is an example, showing r=2 and r=3:

$2.50 in 1986 dollars is



--Dante Alighieri | Talk 19:51, 26 September 2016 (UTC)
 * The bit of code appears to be, which calls the PHP "round" function. The round function apparently drops trailing zeroes after rounding. This is the most concise discussion I have found. It looks like access to the PHP "number_format" feature might fix this problem, but I do not see where this exists in WP.  or , do you know a trick to make the trailing zeroes appear? – Jonesey95 (talk) 21:15, 26 September 2016 (UTC)
 * Jonesey95, might want to look at template:decimals. an easy fix would be to have that template do the rounding. Frietjes (talk) 21:21, 26 September 2016 (UTC)
 * after modifying the sandbox

$2.50 in 1986 dollars is




 * no idea if the change has other side effects. Frietjes (talk) 21:28, 26 September 2016 (UTC)
 * Nice work. That looks like a minor change that should not have side effects, but this template is used in 8,000 pages. Here's the difference in code between the live template and the sandbox. Does anyone here have any comments? I'll give this a day or two before promoting the sandbox code to the live template. – Jonesey95 (talk) 23:14, 26 September 2016 (UTC)
 * Updated. The examples above show that it is working. – Jonesey95 (talk) 03:52, 29 September 2016 (UTC)

Need to update for 2016 data
I just checked the MeasuringWorth.com source for UK inflation rates (link: /ukearncpi), but that website is still limited to 2015. Any ideas where to get estimates for 2016 UK inflation, or other nations, to update Template:Inflation? -Wikid77 (talk) 14:05, 21 October 2016 (UTC)
 * As far as I know, numbers for the current year are just estimates until the year is over. – Jonesey95 (talk) 17:19, 21 October 2016 (UTC)

Subtemplates of {inflation} treated 2016 inflation as 0% since 2015, but I like the idea of putting 2016 estimates (extending 2015) until official figures can be found. Currently, I've read September 2016 data as UK 0.6% and U.S. 1.5% inflation since Fall 2015:
 * "UK inflation rate holds steady at 0.6% - BBC News" (bbc.co.uk)
 * "Current US Inflation Rates: 2006-2016" (usinflationcalculator.com)

Other users have indicated 3rd-quarter rates are close enough for the yearly rate. So, I guess I'll start updating templates to use those multipliers for now. -Wikid77 (talk) 19:28, 21 October 2016 (UTC)
 * Please don't update the US with estimates for 2016. We'll update to the actual numbers next year when they become available. For our purposes, the 2015 dataset is perfectly fine, and if anyone questions it, we can educate people that the actual inflation for 2016 can't be assessed until after the year is over.  Imzadi 1979  →   20:07, 21 October 2016 (UTC)
 * Wait, the inflation data for 2016 has been calculated through September 2016, and the U.S. fiscal year FY2016 has already ended at October 1, with no further changes coming. If there is still concern, I can change the template to indicate "[projected]" when showing the 2016 amount, but there is no technical reason to wait any more months. -Wikid77 (talk) 00:36, 22 October 2016 (UTC)
 * Don't the economic numbers follow the calendar year, not the federal fiscal year? Remember, most states do not follow the federal government's fiscal year start and end dates; in fact only two do and 46 end theirs on June 30. Let's wait until the final numbers are released and stay away from using the projected numbers, ok?  Imzadi 1979  →   05:17, 22 October 2016 (UTC)
 * I note there are knock-on effects to not keeping the table uptodate - I am here after noting errors in the box office numbers for Star wars. Should those editing that table correct the error?  Not sure how to correct the error. Bdushaw (talk) 17:47, 1 January 2017 (UTC)
 * as it stands, the numbers are up to date as of when the series has been calculated. There's always a lag on these sorts of economic numbers. Frankly, I think you're getting ahead of yourself trying to adjust for inflation on those last few figures.  Imzadi 1979  →  18:36, 1 January 2017 (UTC)

How long until 2016 UK inflation update? 50.64.119.38 (talk) 03:41, 17 October 2017 (UTC)

CPI used even for large numbers
A quick check of Special:WhatLinksHere/Template:Inflation revealed that most uses of this template use CPI-based indexes even when adjusting large numbers. This needs to be fixed, but what's the right approach? Not just technically - I imagine it could be done semi-automatically with WP:AWB or the like. Rather, what's the numeric cutoff for which index should be used? Or are there certain categories of figures that should always use one index vs. another regardless of size?--Father Goose (talk) 05:26, 24 November 2016 (UTC)
 * The template is often misused, normally because the editor didn't understand its limitations. The issue is not strictly really one of size, but whether the item being compared fits into the index being used; as per the template page here, the CPI is typically fine for comparing staples, workers' rent, small service bills (doctor's costs, train tickets) over time, but not for the expenditure of the rich, governments, capital expenditure etc. Context therefore matters. But as you suggest there is, in practice, a size aspect to this: average households in the UK today don't frequently buy staple goods costing tens of thousands of pounds, for example (nor have they routinely purchased equivalent goods in historical periods).
 * If I were looking for a editorial guideline to apply to prioritise the identification of problems, I might recommend starting off by identifying uses of the inflation template that produced results of, say, £10,000 plus (or equivalent US) in 2016 terms. Something coming out at that level would probably be a pretty good warning indicator that the template was being misapplied, although I'd still want an editor to check, in the context of the article, that it really had been misapplied (rather than doing so automatically etc.) Hchc2009 (talk) 07:49, 25 November 2016 (UTC)
 * I might have written a few times now, it seems to me that something like movie gross, such as List_of_highest-grossing_openings_for_films, would follow CPI. That is, it is the number of tickets sold times the average ticket price. Maybe it isn't so obvious that a luxury like movie tickets scales with staples like food and rent, but it seems closer than to capital costs. (And yes, that page does use the CPI index.)  I don't know why they measure in gross sales instead of number of seats, but they do.  Does the price of park ranger uniforms, purchased by the government, presumably in large batches, scale by CPI or capital costs? Individual uniforms don't cost that much. Gah4 (talk) 10:13, 25 November 2016 (UTC)
 * One that I have been interested in, is the prices of minicomputers. DEC called their computers Programmable Data Processors, instead of computers, as that allowed them to get through purchasing departments with rules on buying computers. Maybe not so many were bought by individuals, but some by small companies.  Supercomputers were bought by governments and large corporations.  One page I looked at had the total cost of raising an autistic child.  That might be one million dollars over many years, but is spent one little thing at a time.  Maybe we need an index for health care, which, as far as I know, doesn't follow either CPI or capital costs. Gah4 (talk) 10:13, 25 November 2016 (UTC)
 * Historical comparisons of government expenditure definitely shouldn't be using the CPI; the cost of park ranger uniforms (either individually or in huge government volumes) is not something that forms part of a CPI, which is based on baskets of average households expenditure over time. Film tickets in small quantities are part of most CPIs, but whether you would wish to multiply them out in large volumes would depend on the type of comparison you wished to make; for many purposes, a variant of a GDP index would be much more appropriate. Health care is another specialist area in terms of indexes. Hchc2009 (talk) 10:51, 25 November 2016 (UTC)
 * It makes sense to me to inflate something like movie grosses using CPI (even something like the recent Star Wars which grossed around a billion dollars) because it is built up out of lots of small ticket sales. If you actually compare the cost of a movie ticket and CPI there is strong correllation, so it's a good indicator of relative performance which is what the bulk of these articles are interested in. For example, the average price of a movie ticket in 1965 was $1 and last year it was roughly $8. If you adjust $1 by CPI over the same period you get $7.50, so CPI seems to be a pretty good indicator in this regard. A GDP index would be more appropriate if you wanted to show how the movie industry collectively as a whole has dropped over the years as a part of the economy, and if you wanted to assess how a particular movie studio has performed over the course of its existence perhaps GDP per capita, since its perceived success would be strongly linked to its dividend payouts. I think the main reason that the CPI index is used inappropriately is because no other indeces are available through the template, so editors simply use what is there. They take the view that CPI is better than nothing, and in most cases that would be a correct assumption, but ignores the fact that there are better options. Betty Logan (talk) 16:50, 25 November 2016 (UTC)
 * The problem with "scaling up" CPI is that the larger figure is no longer meaningful. Taking the tickets themselves... I'd agree with you that, compared against a basket of average household expenditure, the $1 1965 movie ticket is worth roughly $7.50 in 2016; it means if you took that dollar in 1965 and bought other staple goods with it instead (milk, bottles of beer, a bus ticket etc.), you'd be able to buy the sorts of amounts of things you could buy for $7.50 today. The CPI index is designed to help do exactly that.
 * I'll take the larger number next. If you multiplied out that $1 ticket by the $150 odd million admissions (I think!) that the 1965 Sound of Music film had in the US, you've got $150 million. Using the household CPI that's $1,200 million in 2016 terms. But $150 million was really worth a lot more than that in 1965: it made up a much larger % of the economy than $1,200 million does today. The film's producers, 20th Century Fox, could buy many more shares, companies etc., or finance more new films, with that $150 million than $1,200 million will get you today. Using a share of GDP comparison, $150 million in 1965 is really worth around $3,880 million in 2016 terms - three times as much. CPI simply isn't designed for this sort of comparison, which is why the template notes it constitutes OR.
 * If you want an accessible, but academically grounded, set of essays on this problem, I'd recommend Measuring Worth. Hchc2009 (talk) 17:25, 25 November 2016 (UTC)
 * Thanks for the link but I am already familiar with the economic arguments. The point about adjusting movie grosses and why CPI is better in this particular context is because in these charts it is essentially a proxy for counting movie tickets i.e. we are not esepcially interested in what the studio can do with its $150 million, but how that $150 million was accumulated. According to Box Office Mojo's ticket estimator, The Sound of Music sold 140 million tickets, while last year's Star wars movie sold 110 million tickets, so we can deduce that The Sound of Music performed 25% better, in very basic terms. You can argue that there is more competition around today, multiple viewing formats and so forth, but in basic terms substantially more people watched The Sound of Music at cinemas than The Force Awakens. If you adjust The Sound of Music's gross by CPI inflation you get $1.2 billion, about 30% more than the $936 million The Force Awakens grossed. In that sense CPI inflation is a very accurate indicator of the relative popularity of the two films. Betty Logan (talk) 17:53, 25 November 2016 (UTC)

If we want to compare how many people went to see various films, I'd argue we'd be better off sticking with just stating the numbers of tickets sold. Alternatively, if you do want to use CPI for larger numbers/non-household expenses, simply cite a reliable secondary source that does use CPI as the comparison in the article concerned. Otherwise we're back into original research territory. Hchc2009 (talk) 18:07, 25 November 2016 (UTC)
 * Generally I would agree admissions are a better metric but not all distributors tracked them, and even then there can be substantial variation in ticket prices so there is an argument that admissions aren't flexible enough to account for the value of the ticket. For example an adult ticket for a premium seat on opening night will cost substantially more than a children's matinee ticket at a discount theater three months into a film's run, so CPI offers a level of flexibility that hard admissions don't in comparing the "popularity" of the film. Obviously higher prices drive up box office but drive down admissions, so both metrics can tell a different story. Betty Logan (talk) 18:29, 25 November 2016 (UTC)

Tentative guideline
Thanks for your replies. Can we draw up some rules of thumb for what index to use when and add them to the doc page?

Taking a stab at a general guideline (I'll do what I can to incorporate the discussion so far):


 * Costs of government programs should use NGDPPC.
 * Capital/construction projects, government or otherwise: NGDPPC. If we ever add a construction-specific index, we can selectively switch to that.
 * Capital valuations (large personal estates, corporate market caps, etc.): NGDPPC.
 * Capital earnings: NGDPPC.
 * Consumer goods should use CPI-based indexes.
 * High-end luxury goods: no idea. How have yacht prices changed?  How does one represent the inflation of a Picasso?
 * Salaries should use CPI. But executive compensation, movie/sports stars, etc. – do these track with capital figures?
 * Aggregate figures of consumer goods, such as movie grosses: unresolved. Even if the underlying inflator is consumer-based, a large sum starts to take on meaning as a "slice of the economy" (GDP).  But in this specific case, the figure may simply be a proxy for "number of tickets sold".  Do other sites/publications generally use a CPI-based adjustment for movie grosses?  If so, we should do the same, on the principle of least surprise.
 * Bulk purchases of consumer goods (such as uniforms): Unresolved. Again, large sums start to represent a slice of the economy.  Furthermore, there are infamous cases of $640 toilet seats.  I'm leaning NGDPPC on this one.
 * Medical costs: no idea.
 * Real estate: no idea. As I understand it, the CPI includes rent costs as part of its basket.  A little research turns up the Case–Shiller indexes, which seem to track CPI reasonably well, unless I'm totally misreading it.  So even if CPI is a fair approximation for normal housing (is it?), what's appropriate for luxury housing or commercial real estate?  How many units in an MDU before it becomes more than a house?
 * Are there other categories that warrant special treatment/indexes?

Comments?--Father Goose (talk) 18:16, 25 November 2016 (UTC)


 * The MeasuringWorth site has some examples: . I would say a luxury yacht reflects "economic status" so "per capita GDP" is advised here. Betty Logan (talk) 18:41, 25 November 2016 (UTC)
 * Well, all right, I wasted a bullet with my luxury examples; yachts and Picassos are definitely not consumer items. But at what point does a car or a boat become a capital expenditure instead of a commodity?  Should the figures at Dom Pérignon be adjusted with CPI or GDP?  And since I brought up Picassos, list of most expensive paintings uses CPI; in line with everything discussed so far, it sounds like this should be changed to GDP.  Other publications discussing expensive paintings seem to use CPI but I suspect most of them just lifted their figures from Wikipedia (a few explicitly say as much).--Father Goose (talk) 03:23, 26 November 2016 (UTC)
 * Agree with Betty - per capita GDP. Hchc2009 (talk) 08:16, 26 November 2016 (UTC)
 * Consumer goods - usually CPI, particularly over shorter periods (e.g. comparing 1965 to 1975 say), but there will be circumstances where the earnings index would be better - typically longer periods (e.g. comparing 1900 and 2000). Hchc2009 (talk) 08:16, 26 November 2016 (UTC)
 * Salaries - really depends on what you're trying to explain. CPI's poor for this one over any length of time, when you'd really want an average earnings or even a GDP measure. Hchc2009 (talk) 08:16, 26 November 2016 (UTC)
 * Bulk purchases. Almost by definition, not a household expense. Per capita GDP would probably work best. Hchc2009 (talk) 08:16, 26 November 2016 (UTC)
 * Medical costs. Small medical costs (visiting a private doctor) would form part of CPI in some countries (but not all). Larger medical costs (e.g. for a large operation, or a new piece of equipment) wouldn't be included; there are some specialist indexes, or you could fall back on per capita GDP indexes. Hchc2009 (talk) 08:16, 26 November 2016 (UTC)
 * Real estate. CPI includes rent (although RPI doesn't), but not capital - i.e. it is appropriate for comparing $500/month rent, but not the $250,000 value of a condo. For the latter you'd probably be after a GDP measure. Hchc2009 (talk) 08:16, 26 November 2016 (UTC)
 * As ever, may be specific exceptions why one measure is more appropriate than another, of course - it would depend on the context. Hchc2009 (talk) 08:16, 26 November 2016 (UTC)


 * I am not an economist, but here is how I would think about it. Prices are set by supply and demand, by competition.  If some goods compete with each other, their prices will tend to track. Consumers can decide between toys and games, or movie tickets, for their entertainment value, so I would expect them to track. As well as I know it, the salaries of CEOs aren't tracking with the salaries of ordinary workers, and as far as I know, not with government capital expenditures.  You might need a different index for yachts and Picassos. I suppose government construction projects (bridges and such) might compete with large corporate construction (factories), and so might have some tendency to track.  Military grade electronics tend to be more expensive than consumer electronics, because they have to meet higher standards.  They aren't bought in such high volumes, and so lower economy of scale, and they do compete with other government expenses.  If the park ranger uniforms are made in the same factories that make other clothes, they should compete for resources, and the prices should track. Maybe they are a little higher quality, so don't track quite the same, but maybe not so far off.  In the case of many government projects, I don't really care how much it costs, but how much it costs me.  That is, in taxes and such. As populations increase, there will be more people pay for a large government project.  It shouldn't be surprising that government sized project prices increase along with population increases. Gah4 (talk) 08:37, 26 November 2016 (UTC)
 * OK, so it seems to me that we need an index for expenses for the top 1% or 0.1% income brackets, and also for health care costs. Gah4 (talk) 08:37, 26 November 2016 (UTC)
 * At the moment there are two indeces, at least for the US and UK. Guidelines always work best when they are uncomplicated. I would say that as a basic rule of thumb when you are comparing the cost of something then use the CPI for affordable costs, that is something you can afford on a typical monthly salary i.e. rent, a new laptop, a movie ticket, a loaf of bread etc. Everything else such as wages, the cost of a house, a multi-million dollar bonus, a luxury yacht etc should probably use NGDPPC (GDP per capita). Obviously there will be exceptions (such as the movie gross example above which depends on what you are actually trying to measure) but I reckon basic rule of thumb would easily cover the majority of cases. Things could become more nuanced if further indeces are added (such as a salary index) but at the moment the guideline only needs to reflect what is actually there. Betty Logan (talk) 02:26, 30 November 2016 (UTC)
 * At this point I would say you've stretched this well beyond its utility. CPI and NGDPPC are only broad rough estimates across the entire country; how can you use them to compare the cost of an open-heart surgery in 1967 at NYU by an experienced surgeon with the cost of a pacemaker implantation in 1998 at Davis by a resident? How can you compare real estate price changes in Stockton, California to real estate price changes in Des Moines, Iowa, which was relatively unaffected by the recession? These are nothing more than a guide to help readers try to put old numbers into a current context, despite being impossible to do fully, so you don't have to go down a rabbit hole chasing perfection. I agree with the general idea that if it's something bought by a regular person (including medical and real estate), it's CPI, otherwise it's capital, because that's probably as close as we're going to get to a usable rule of thumb. -- SilverbackNet talk 08:48, 19 February 2017 (UTC)

Template error
Look at Template:Inflation/doc. It's full of " Error when using : NaN, check parameters for non-numeric data: |end_year= (parameter 4) and |r= " messages. Can someone fix, please? Thanks. — howcheng  {chat} 08:18, 29 November 2016 (UTC)
 * I don't have time to check now, but I just left a message here based on a guess. Johnuniq (talk) 10:20, 29 November 2016 (UTC)
 * I have the same problem... hope it gets fixed soon as it is currently breaking all instances of this template which defaults to the latest available year. Deryck C. 11:04, 29 November 2016 (UTC)


 * Seems to be that any use without both end_year and r would fail, due to a change in isnumeric. I reverted the changes to isnumeric without figuring out why it was changed, and purged this page. Purge any other pages with ?action=purge  appended to the URL. Gah4 (talk) 11:07, 29 November 2016 (UTC)
 * ✅ This has been [ fixed]. Od1n (talk) 02:35, 30 November 2016 (UTC)

Additional currencies
How would we go about adding more currencies to this template?  Schwede 66  22:24, 9 December 2016 (UTC)

start_year=2,016 causing template error
There is a problem with the template using the 2016 dates at List_of_highest-grossing_films_in_Canada_and_the_United_States:

The problem isn't just limited at this article either and seems to be widespread across Wikipedia. Betty Logan (talk) 21:10, 2 January 2017 (UTC)
 * I see you updated Inflation/US/dataset. I have made the corresponding update to Inflation-year.[//en.wikipedia.org/w/index.php?title=Template:Inflation-year&diff=757989721&oldid=745413842] The job queue should clear out those pages in Category:Pages with errors in inflation template which were caused by US 2016. PrimeHunter (talk) 21:48, 2 January 2017 (UTC)

continuum?
In much of this page, there is a distinction between CPI based and GDP/capita based indexing. But is it really one or the other? Could it be a continuum, where one could select a number between 0 and 1, where 0 gives CPI, 1 gives GDP/capita, and values in between give an inflation rate somewhere between? This doesn't help much for things that likely have a completely unrelated index. I will guess that health care costs and rare paintings don't closely follow one of the indices so far implemented. A continuum might require some fundamental changes in the template, though. Gah4 (talk) 10:26, 21 April 2017 (UTC)

Russian roubles
If the data for Russian roubles is available it would be useful to add this, e.g. for articles like Kursk submarine disaster. Thryduulf (talk) 19:22, 12 August 2017 (UTC)

Limits to useability? Or better data points?
How far back can this template be used - reliably? There seems to be a large discrepancy a hundred years ago, where the template may say $ but other sources say $96,000 for 2016. The template seems to use GDP as the guideline, but also differs considerably (at $) from a specific GDP-estimate at $33,000 in 2015-prices. One source could be wrong, but two different sources combined seems to indicate a fundamental problem. I stumbled upon the issue here. TGCP (talk) 00:26, 8 October 2017 (UTC)
 * It really depends which series you use. The "$22,000 in 2016" figure at Ford_Model_T uses the consumer price index template (CPI), whereas the "$96,000 in 2016" figure does not use a template. It is probabbly derived from some GDP related measure though. These are the two figures you get using Wikipedia's two options:
 * $ inflates to $ in (CPI)
 * $ inflates to $ in (GDP per capita)
 * Obviously the further we get from the event the greater the divergence between the two measures. Which index you use purely depends on what you use it for and there is no truly correct answer here. If you are comparing the cost of the car to say the average cost of transportation (which is probably a primary factor in deciding whether to buy a car or not) then CPI is probably the correct measure, but if you want to compare its affordability to today's buyers then a wage index or GDP measure is probably a better choice. Let's put it this way, buying a car back then would hurt your wallet as much as buying a Ferrari today so the GDP per capita probably produces the more relatable figure. A dock worker can afford a car today but it would have been totally out of his price range in 1909. Betty Logan (talk) 12:15, 8 October 2017 (UTC)

2016 UK Inflation Available.
The 2016 numbers are available at the site the UK Inflation template uses for reference. The percent diffences between 2015 to 2016 are here.UK Inflation Change 2015 - 2016 Perhaps someone could update the template? 50.64.119.38 (talk) 04:27, 17 October 2017 (UTC)

Computers
OK, the one that I most often run into is inflation adjustment on the price of computers from the 1960's. There is currently disagreement on using US or US-GDP on one computer. But even more strange, the current state has one for the purchase price and the other for the lease price. So, which one for computer prices? Gah4 (talk) 05:16, 21 January 2018 (UTC)


 * You're apparently referring to IBM 7090, which at $3 million in 1960, is most definitely not a household expense. US-GDP.  Leasing should also use US-GDP; the expense is on a comparable scale, but paid in increments.--Father Goose (talk) 19:11, 21 January 2018 (UTC)


 * Yes, I suspect that most who buy actually finance, so have a monthly payment similar to a lease payment. But the expense is about the same either way. I was surprised why some editors would change one and not the other. Gah4 (talk) 20:36, 21 January 2018 (UTC)

broken template
The inflation template was added to the USS Enterprise (CVN-65) infobox "original cost" parameter back in July 2016. Today I noticed it was showing an error message and so I've removed it for now. The history shows you two edited this template since, do either of you know what changes may have occurred to create the error? Is new formatting needed? It would be good for the article if a working template could be re-added. Thanks - the WOLF  child  15:33, 24 January 2018 (UTC)
 * The errors happen with and  (undefined index "US-NGDPPC"). Od1n (talk) 16:21, 24 January 2018 (UTC)
 * the  index was removed. Instead,   should be used instead.  Imzadi 1979   →   18:16, 24 January 2018 (UTC)

Thanks guys, I've got the correct template in there now. - the WOLF  child  18:36, 24 January 2018 (UTC)
 * I have a quick suggestion for you. The USS Enterprise article uses citation for its footnotes, which means it's using Citation Style 2 formatting. Inflation-fn uses cite web as a base template, so it uses Citation Style 1. If you add cs2 to inflation-fn, it will switch to CS2 from CS1.  Imzadi 1979  →   19:03, 24 January 2018 (UTC)
 * I appreciate the reply, but I'm not entirely familiar with these templates, or these cite formats. After playing around with it for a few minutes (and several page previews), I ended up copying the template from another article's infobox. If you think this article would benefit from some parameter change, by all means, please go ahead and switch it up. Thanks again - the WOLF  child  19:26, 24 January 2018 (UTC)

Somewhat unrelated: I have added as a tracking category to those two additional Inflation templates in order to turn up more instances of problems like this. Tracking categories like this have proved very helpful in fixing errors in many other templates. – Jonesey95 (talk) 04:11, 25 January 2018 (UTC)