The relative importance of cultural and economic issues for the polarization

We develop a simple model in which voters care about both economic and “cultural” policy (noneconomic issues such as abortion). Democrats and Republicans are ideologically differentiated and choose economic policy positions to maximize their respective probability of winning. Voters who are culturally and economically conservative or liberal strongly prefer one of the parties, while the boundary between the set of Democratic and Republican supporters is along a economically-conservative-sociallyliberal to economically-liberal-socially-conservative line. The change of the slope of this line over time tells us about changes in the relative importance of cultural and economic issues for vote choice. Using data from the American National Election Survey, we structurally estimate the model and show that the distribution of voter preferences in the American electorate remained relatively constant over the last 35 years. However, the importance of cultural factors relative to economic issues for the vote choice has increased significantly over the last generation. Also, policy preference intensity has increased substantially over the same time frame. These results are consistent with a view that parties have become much more internally homogeneous on cultural issues over the last generation, and that this is the factor that is driving polarization.