Demographic Change and Political Polarization in the United States

I construct an index of political polarization using seven previously proposed measures. I estimate the relative propensity for polarization across demographic groups in a regression framework and examine the extent to which demographic change can explain recent trends in polarization. Assuming fixed propensities for polarization, I estimate that 25 to 59 percent of the change in polarization between 1984 and 2016 can be attributed to demographic change in the United States. ∗E-mail: [email protected]. I thank Matthew Gentzkow and Jesse M. Shapiro for their comments and suggestions. I acknowledge funding from the National Science Foundation (grant number: DGE-1656518) and the Institute for Humane Studies. The American National Election Studies and the relevant funding agencies bear no responsibility for use of the data or for interpretations or inferences based upon such uses.