In this paper we expand our understanding of language endangerment by shifting the focus from small language communities to minority language communities with speaker populations in the millions. We argue for a methodological shift toward examining language shift scenarios more broadly and quantitatively for two main reasons: 1) it is becoming increasingly clear that a large speaker population does not protect against language shift (Anderbeck 2013); 2) we need to make a distinction between the symptoms and the causes of language shift, where factors such as a dwindling number of child speakers should be seen as symptoms of language shift that are caused by other factors (Himmelmann 2010). In this paper we use Indonesia as a case study and analyze a sample of the 2010 census. We treat language choice as a sociolinguistic variable and analyze the correlation between six social factors and language choice (local languages vs. the national language, Indonesian). These results provide a starting point for creating more comprehensive models of the sociolinguistics of language shift.