Learning by lobbying

Abstract Effective lobbying requires understanding politicians' preferences, while the act of lobbying itself can reveal those preferences. How does this link between lobbying and learning shape relationships between interest groups and politicians? We develop a game‐theoretic model where an interest group can lobby a politician while learning about their ideological alignment. Our analysis highlights strategic tensions where interest groups balance information‐gathering against policy influence in their lobbying, while forward‐looking politicians manage their reputations to shape future interactions. These forces shape dynamics: Policies and transfers shift over time as uncertainty resolves, with early‐career politicians showing greater policy variance and extracting larger benefits through reputation management than veterans. Politicians with secure positions receive more favorable treatment due to their stronger incentives to appear less aligned than they truly are. Our results address empirical regularities and provide a theoretical foundation for understanding how lobbying relationships evolve across political careers and institutional contexts.