THE DETERMINANTS OF SUCCESS OF SPECIAL INTERESTS IN REDISTRIBUTIVE POLITICS

We examine what determines whether an interest group will receive favo rs in pork-barrel politics, using a model of majority voting with two competing parties. Each group's membership is heterogeneous in its ide ological affinity for the parties. Individuals face a trade-off betwee n party affinity and their own transfer receipts. The model is general enough to yield two often-discussed bur competing theories as special cases. If the parties are equally effective in delivering transfers t o any group, then the outcome of the process conforms to the ''swing v oter'' theory: both parties woo the groups that are politically centra l, and most willing to switch their votes in response to economic favo rs. If groups have party affinities, and each party is more effective in delivering favors to its own support group, then we can get the ''m achine politics'' outcome, where each party favors its core support gr oup. We derive these results theoretically, and illustrate their opera tion in particular examples.