Measuring ethnic voting: Does proportional representation politicize ethnicity?∗

This paper develops a measure that can be used to compare ethnic voting levels across countries. The measure examines the relationship between ethnicity and vote choice: as it becomes easier to predict voting behavior in a country by knowing only voters’ ethnicity, the ethnic voting measure increases. The paper then uses data from 71 surveys to estimate ethnic voting levels in 45 countries, and to examine the validity of the widely held assumption that proportional electoral laws lead to higher levels of ethnic voting. The central finding is that all else equal, proportional representation leads to less rather than more politicization of ethnicity. By examining patterns of vote support across ethnic groups, the paper suggests explanations for why PR often leads to less ethnic voting than is generally assumed. ∗I am grateful for research assistance from Tom Ogorzalek, for research support from the National Science Foundation, and for helpful comments from Kate Baldwin and Dawn Brancati. I am also grateful to the Russell Sage Foundation, where I was a visiting research scholar while writing this paper. †Professor, Department of Political Science, Columbia University, and Visiting Scholar, Russell Sage Foundation, New York.