The Informational Value of Incumbency

This paper proposes an argument that explains incumbency advantage without recurring to the collective irresponsibility of legislatures. For that purpose, we exploit the informational value of incumbency: incumbency confers voters information about governing politicians not available from challengers. Because there are many reasons for high reelection rates di¤erent from incumbency status, we propose a measure of incumbency advantage that improves the use of pure reelection success. We also study the relationship between incumbency advantage and ideological and selection biases. An important implication of our analysis is that the literature linking incumbency and legislature irresponsibility most likely provides an overestimation of the latter. Key words: Incumbency, information, candidate quality, selection bias, ideology. JEL Classi…cation Number(s): D72, D78. We thank Enriqueta Aragonés, Luis Corchón, and Paula González for helpful comments and suggestions. This research has been supported by Barcelona Economics program (CREA). Carmen Beviá acknowledges …nancial support from grants SEJ200501581/ECONFEDER, and 2005SGR-00454. Humberto Llavador acknowledges …nancial support from grant BEC2003-00412 and the European Commission (contract n. HPSE-CT-199000007) yDepartament d’Economia i d’Història Econòmica and CODE. [email protected] zDepartament d’Economia i Empresa. [email protected] Barcelona Economics WP no 276