Electoral Competition with Two Major Parties and Two Minor Parties

The purpose of this article is to study a one-dimensional model of spatial electoral competition with four political parties. In this model, voters are divided into two types, the informed voters and the uninformed voters. Informed voters vote based on the policies from the four candidates, meanwhile uninformed voters vote based on the party’s expenditures that come from interest groups. Furthermore, we assume that the two of the four parties are major parties and the other two are minor parties. As major parties, they have reputational advantage; some of the informed voters only vote between two major parties according to their platforms. In this situation, we present various shaped of political equilibrium, and show their voting share in equilibrium.