His primary research area is comparative politics with an emphasis on mass political behavior in East-Central Europe and the former Soviet Union, including elections and voting, partisanship, and public opinion formation. He is the author of Regional Economic Voting: Russia, Poland, Hungary, Slovakia, and the Czech Republic, 1990-99 (Cambridge University Press, 2006). His work has also appeared in numerous academic journals, including the American Journal of Political Science, the Annual Review of Political Science, Communist and Post-Communist Studies, Electoral Studies, the Journal of Politics, Perspectives on Politics, Party Politics, Political Analysis, and Post-Soviet Affairs.