選挙におけるネガティブ・キャンペーンの役割

抄録

This paper examines campaign strategies of parties in elections, and investigates a role of a negative campaign. It shows that a negative campaign can be an optimal strategy in some cases. One interesting case is that one party chooses a positive campaign that accommodates its pledge to that of opponent and the other party chooses a negative campaign that discriminates opponent's pledge from its own in a Nash equilibrium. Although positive campaigns only reveal positive effects of policies, the negative campaign works to reveal negative effects of the opponent's policy. Thus negative campaigns contribute to show the true effects of policies to voters.