Silent promotion of agendas: campaign contributions and ideological polarization

摘要

We set up a two-party electoral competition model in a two-dimensional policy space with campaign contributions by an interest group that wants to promote a certain agenda. Assuming that voters are influenced by campaign spending for/against candidates, we analyze incentive-compatible contracts between the interest group and the candidates on agenda policy positions and campaign contributions. The interest group asks the candidates to commit to a level of agenda promotion in exchange for campaign contributions, letting them compete over the other (ideological) dimension only. It is shown that as the agenda is pushed further by the interest group, ideological policy polarization and campaign contributions surge.