Key points are not available for this paper at this time.
In 1956, Greenberg proposed eight measures of linguistic diversity designed to determine the possibilities of communication among the population of some delimited area. Taking note of the considerable variance between areas of the world in their linguistic diversity, Greenberg's measures allow us to quantify this diversity on a continuum ranging from complete diversity, such that no two people speak a mutually intelligible language or dialect, to the other extreme, where all inhabitants share a common tongue. By going beyond mere verbal descriptions of an area's linguistic diversity, these quantitative measures enable us to correlate language usage with social, economic, political, and geographic factors.
Stanley Lieberson (Tue,) studied this question.