Attract voters or appease activists? Opposition parties’ dilemma and party policy change

Why do mainstream opposition parties sometimes fail to adopt policy positions that are attractive to the wider electorate? In this paper, I construct a game-theoretic model between the party leader, the party’s MPs, and the party organization to illustrate how opposition parties’ platform adjustments depend on the party leader’s risk assessment of being deposed and MPs’ re-election incentives. The model predicts that a party leader is most likely to adhere to the activists’ position when MPs’ re-election probabilities depend greatly on activists’ campaign effort, and when MPs’ benefits of re-election are high. Platform adjustments are only possible when the reverse is true. These results have important implications on electoral competitiveness and strategies of parties in majoritarian versus proportional electoral systems. Namely, I expect that opposition parties in majoritarian systems are less able to adjust their platforms than those in proportional systems.