Ethan Mollick, a professor at the Wharton business school, Tweets about a paper that causally links student loan debt with declining entrepreneurship in America (including in high-growth, high-tech activities). By exploiting two “exogenous shocks” to the student loan system (public policy changes that are unrelated to entrepreneurship), the authors demonstrate that student loan debt not only causes individuals to start fewer businesses (especially in the high-tech, high-growth segments), but when they do, they are (a) less likely to be successful, and (b) experience greater hardship from the (already more likely) business failures. These are not exactly the type of conditions that encourage people to start new ventures, particularly when competing in a harsh competitive environment of increasing market power, raising incumbency advantage, and expanding wage opportunities at larger companies.