Linguistic demography

Linguistic demography is the statistical study of languages among all populations. Estimating the number of speakers of a given language is not straightforward, and various estimates may diverge considerably. This is first of all due to the question of defining "language" vs. "dialect". Identification of varieties as a single language or as distinct languages is often based on ethnic, cultural, or political considerations rather than mutual intelligibility. The second difficulty is multilingualism, complicating the definition of "native language". Finally, in many countries, insufficient census data add to the difficulties.

Demolinguistics is a branch of Sociology of language observing linguistic trends as affected by population distribution and redistribution and by the status of societies.

Most spoken languages
The following table compares the estimates of Comrie (1998) and  Weber (1997) (number of native speakers in millions). Also given are the estimates of SIL Ethnologue (2005). Comparing estimates that do not date to the same year is problematic due to the 1.14% per year growth of world population (with significant regional differences).

This table shows that for the world's largest languages, it is impossible to give an estimate of the number of native speakers with a certainty better than maybe 10% or 20% or so.

Literature

 * Johanna Nichols, Linguistic Diversity in Space and Time, University of Chicago Press (1992), ISBN 978-0-226-58056-2.
 * David I. Kertzer and Dominique Arel (eds.), Census and Indentiry : The Politics of Race, Ethnicity, and Language in National Censuses, ISBN 978-0-521-80823-1.
 * Jacques Pohl, Demolinguistics and Language Problems (1972).
 * H. Kloss, G. McConnell (eds.), Linguistic Composition of the Nations of the World vol. 2, North America, Quebec (1974–1984).