Political Accountability, Electoral Control, and Media Bias

Are anti-establishment mass media really useful in preventing politicians from behaving dishonestly? This paper proposes a voting model for analyzing how differences in the direction of media bias affect politicians' behavior. In particular, the probability of corruption by an incumbent is higher (than that in the case of no media bias) if and only if the mass media have some degree of "anti-incumbent" bias (i.e., information favorable to the incumbent is converted into unfavorable news about him or her with a positive probability), provided that the incumbent is less likely to be opportunistic than a challenger. This result holds irrespective of the degree of "pro-incumbent" bias (i.e., information unfavorable to the incumbent is converted into impressive news about him or her with a positive probability). We also show that media bias never increases voter welfare. Our results thus suggest that society should make an effort to eliminate media bias per se rather than promote antagonistic media.