Campaign finance legislation and the supply-side of the revolving door

Existing research on the revolving door examines why employers hire former politicians. I complement this demand-side approach by demonstrating the importance of the supply-side. In particular, I argue that one important institutional factor that shapes politicians' willingness to leave office for a private sector job is campaign finance legislation. Less restrictive rules increase campaign spending for incumbents, which makes revolving door employment less attractive. Empirically, I use novel data from the US states and a difference-in-differences design to show that the exogenous removal of campaign finance legislation through Citizens United reduced the probability that incumbents left office to work as lobbyists. The supply-side approach provides insights into comparative differences in the prevalence of the revolving door.