File talk:Gdp20-40.jpg

I have three problems with this chart:

1. The citation is quite incomplete and that will make it harder for readers to look it up. Why not use the source's own suggested citation? This is:
 * Sutch, Richard, "Gross domestic product: 1790-2002 [Continuous annual series]." Table Ca9-19 in Historical Statistics of the United States, Earliest Times to the Present: Millennial Edition, edited by Susan B. Carter, Scott Sigmund Gartner, Michael R. Haines, Alan L. Olmstead, Richard Sutch, and Gavin Wright. New York: Cambridge University Press, 2006.

2. The source is no problem for those of us with access to research libraries, but is a problem for those not so blessed, who would have to pay for access. Why not use a source which is more accessible and also more up-to date? You could just change the attribution, becuase I'm reasonably sure that none of the values over this period are enough different to show up at this scale. My suggestion would be:
 * Louis D. Johnston and Samuel H. Williamson, "What Was the U.S. GDP Then?" MeasuringWorth, 2008. URL:.

3. What is the curving black line? It certainly it not in the cited source, which I've just checked. Is it a regression line? If so the reader needs to be told how the regression was done and what the meaning of the line is. Will O&#39;Neil (talk) 18:53, 5 March 2009 (UTC)

One further concern:

4. This is a linear-scale graph with a non-zero origin for the y-axis, which in general can be very misleading for unwary users. Either it should be re-drawn with a zero origin or readers should be alerted to the non-zero origin and the reasons for selecting it at every place it appears. My preference would be very much for the former. An alternative would be to plot it on a log scale. Will O&#39;Neil (talk) 19:03, 5 March 2009 (UTC)