Emily Badger examines the correlation between the arrival of ride-share services and a noticeable drop in DUIs, both in Philadelphia and in San Francisco:

We’ve simply plotted arrests on a timeline here; we haven’t adjusted for changes in the city’s population, or bar scene, or the economy. Any number of other things may have changed in the city over the last few years affecting DUI arrests. … These data, though, do suggest that there’s at least more to research here. They remind me of a comment Lyft’s VP for government relations, David Estrada, made to me recently. “As a company — this might sound pollyanish — we talk about our service not being aimed at providing transportation,” he said, “but at lowering crime rates in a city like Chicago.”

DUIs are potentially one way this might happen. If these services, which run on credit cards, take cash out of transactions as well, they may also cut down on other kinds of crime like theft (this is an argument Uber has made in Chicago). Estrada was also simply talking about the idea that crime might decline because Lyft likes to think that it creates community — and jobs in communities that don’t have enough of them. That last argument merits a lot more skepticism. DUIs, though, we might actually wrap our arms around.