` To solve the actuation problem, Labov proposes to study the "mechanism of change" in language. `
He describes this mechanism in terms of performance variability within a community. The boundaries of community are chosen on non-linguistic grounds to avoid circularity. {<[LINK]> go to Labov on speech community} Linguistic variability is then correlated to such independent variables as class position, age, performance style and register. He equates this mechanism of community-wide variation with an explanation of why language changes by saying that the correlations that he has found can be used as causal explanations, or at least, as the best guesses. Precisely when Labov posits the mechanism as the explanation he succumbs to the empiricist's sorest temptation, namely, attributing cause to correlation.<[LINK]> This is the leap from "what" to "why." It becomes necessary at precisely the point at which Labov seeks to engage the problems he raises in his critique of the neo-grammarians, structuralists and Chomsky.