@treycausey tweeted about this Uber blog post about how Uber reduced DUI arrests in Seattle. Using a technique called regression discontinuity, they claim that Uber has reduced DUI arrests by about 10% on average. The post bugged me though, because there is not a lot of detail on the methods, and regression discontinuity is the sort of research design that is very much dependent on specification. In this post I replicate the study and walk through what regression discontinuity is and why it can be a very effective research design. Ultimately I think it’s plausible that Uber did in fact reduce DUIs in Seattle, but the story is a bit more complex than the blog post lets on. Continued under the break!