Linguistic system and sociolinguistic environment as competing factors in linguistic variation: A typological approach

Abstract This paper brings together typological and sociolinguistic approaches to language variation. Its main aim is to evaluate the relative effect of language internal and external factors on the number of cases in the world’s languages. I model word order as a language internal predictor; it is well-known that, for instance, languages with verb-final word order (that is, languages in which both nominal arguments precede the main lexical verb) tend to develop complex case systems more often than languages with SVO word order do. I model population size and the proportion of second language speakers in the speech community as sociolinguistic predictors; these factors have been suggested recently to influence the distribution of the number of cases in the world’s languages. Modelling the data with generalized linear mixed effects modelling suggests an interaction between the number of cases, word order, and the proportion of second language speakers on the one hand, and between the number of cases, word order, and population size, on the other. This kind of complex interactions have not been previously reported in typological research wherefore they call for more complex explanations than previously suggested for cross-linguistic variation.