Expertise, networks, and interpersonal influence in congress

Abstract

Legislators often must vote on complex issues that they do not fully understand. I show that legislators cope with incomplete information by taking cues from trusted peers who possess expertise that they themselves lack. With a matched differences-in-differences design that exploits midsession committee assignments as expertise-increasing events, I estimate that this behavior accounts for a substantial proportion of all congressional voting decisions. These cues cross party lines and remain relevant in the face of mounting partisan polarization. My findings highlight the salience of expertise to legislators and the role that ties between legislators play in allowing Congress to reach informed collective decisions.