Multimember district congressional elections

In the Apportionment Act of 1842, the House of Representatives mandated single-member districts (SMDs) for elections of its members. Before this act, many states had multimember districts (MMDs), and even after this act, Congress permitted some exceptions up until 1967. This paper addresses several questions related to the election of representatives in MMD elections. Herein, I develop a model of MMD elections that predicts that one party will sweep all the seats in this type of election. I then perform empirical analyses to examine and validate the four key assumptions of the model. My prediction that one party will sweep all the seats in an MMD election is verified by examining the actual results of all MMD House races in history. In this paper, I also show that, in general, the diversity of a state's House delegation increases when the state shifts from general-ticket to single-member districts, but diversity decreases when the state moves in the opposite direction.