Title: Bound Together: Racial Peer Effects and Caucus Control in the U.S. Congress

Abstract: This paper argues that MCs’ social groups and the norms of behavior that define them can powerfully constrain legislators’ behaviors. Guided by insights from scholarship on legislative organizations and identity politics, I test my argument using the case of Black MCs and the Congressional Black Caucus (CBC). My main empirical strategy uses an original data set of committee hearing transcripts from 2007 to 2019 and a design that exploits members’ exposure to fellow Black MCs on their various committee assignments to uncover the impact of group pressures on CBC members. I show that the effect of serving on a committee with more co-ethnic legislators varies by a given MC’s type: Members that are more aligned with the interests of the CBC — those that are left-leaning and represent more-Black Congressional districts — participate more in committee hearings, and members that are less aligned participate less. I then show using a series of empirical tests and qualitative evidence drawing on eliteinterviews that this pattern of results is driven by in-group sanctions for behavior that is inconsistentwith caucus wishes. Together, the theory and findings shed light on the role of groups and their norms in shaping elite behavior and provide evidence for the contextual nature of legislative Black political behavior.