What can historical linguistics and experimental pragmatics offer each other?

Language change is a central concern for any linguistic theory. For one thing, it is often assumed that language change is explanatory, in that it provides a reasonable answer to what Haspelmath dubbed 'Greenberg's Problem' in 2014: Why are languages the way they are? A short version of the Greenbergian answer is: 'Because they became that way through processes of language change.' However, this sort of answer throws into focus the fact that language change is not only a potential explanation for language structures. Rather, it is a set of problems that itself calls for explanation. In fact, this could be called 'Greenberg's Second Question': Why do languages change the way they do? In this article, we explore some ways in which the field of experimental pragmatics might shed light on the second question, by providing a set of methods that could investigate existing hypotheses about language change by developing falsifiable predictions to be evaluated in experimental settings. Moreover, these hypotheses can provide new research questions and data for experimentalists to work on, beyond the rather restricted set of questions that experimental pragmatics has confronted to date.