Unidimensional Voting and Multidimensional Issues: The Role of Interest Groups

Voting on unidimensional issues will produce equilibrium outcomes if voter preferences are single peaked. While the equilibrium outcomes would not necessarily be Pareto optimal, they would be stable. This paper shows that voting on multidimensional issues can produce stable equilibria if the voting occurs in one "super" ideological dimension. However, interest groups that expect to lose the ideological vote have an incentive to disrupt the voting process by arguing that the voting should not be ideological.