Are the World's Languages Consolidating? The Dynamics and Distribution of Language Populations

Scholars have conjectured that the return to speaking a language increases with the number of speakers. Long-run economic and political integration would accentuate this advantage, increasing the population share of the largest languages. I show that, to the contrary, language size and growth are uncorrelated except for very small languages (<35,000 speakers). I develop a model of local language coordination over a network. The steady-state distribution of language sizes follows a power law and precisely fits the empirical size distribution of languages with ≥35,000 speakers. Simulations suggest the extinction of 40% of languages with <35,000 speakers within 100 years.