This paper examines the impact of dynastic political privilege on the behavior of incumbents. Incumbents have opportunities to serve themselves at the expense of voters, but society can design political institutions to mitigate these principal-agent problems. Dynastic political privilege may be one such mechanism. We argue that the possibility that opportunistic behavior in office may damage family members' political prospects disciplines incumbents. We test this hypothesis using data for 1950–2005 on U.S. governors, including a new data set on the family relationships of politicians, and find that dynastic political privilege increases incumbent accountability. (JEL H71, H10)