My research both theoretically and empirically asks which factors shape political competition in democracies. For example, why do some countries have more political parties than others, and why do ethnic issues only sometimes appear on the political agenda? These research questions are important to comparative politics because political competition in turn shapes both public policy and the character of the democratic process.

I am currently working on a book manuscript that is very loosely based on my dissertation. This book explores how changes in society that increase the heterogeneity of the citizenry, from immigration to expansions in the franchise, shape democratic political competition; the ways in which political institutions and other factors (both systemic and group-specific) condition this process; and the normative implications of the different paths to political representation that new social groups can take. More specifically, it asks (1) whether new social groups are successful at forming their own sectarian political parties and why and (2) whether it matters for democratic representation if they are. Israel (Sephardi and Russian Jewish immigration) and the United States (African American enfranchisement) are the two case studies. I am also currently working on several articles.

Replication data sets for published articles are available as tab-delimited text files (denoted [TXT]) and sometimes additionally as Microsoft Excel files (denoted [XLS]). Codebooks for these replication data sets are available either as PDF files (denoted [PDF]) or as text files.

Publications (Peer Reviewed)

Dimensionality and the Number of Parties in Legislative Elections. N. d. Party Politics. Forthcoming. [PDF] || Supplemental Materials [PDF]

Presidents and Parties: How Presidential Elections Shape Coordination in Legislative Elections (with Allen Hicken). 2011. Comparative Political Studies 44 (8). Forthcoming. [PDF] || Supplemental Materials [PDF]

Elite Level Conflict Salience and Dimensionality in Western Europe: Concepts and Empirical Findings. 2010. West European Politics 33 (3). Forthcoming. Also forthcoming in Zsolt Enyedi and Kevin Deegan-Krause, eds., The Structure of Political Competition in Western Europe, Routledge. [PDF] || Supplemental Materials [PDF]

What Moves Parties? The Role of Public Opinion and Global Economic Conditions in Western Europe (with James Adams and Andrea Haupt). 2009. Comparative Political Studies 42 (5): 611-639. [LINK] [PDF] || Supplemental Materials [PDF] || Replication Data [XLS] || Replication Data Codebook [PDF] || Errata [PDF]

Social Cleavages and the Number of Parties: How the Measures You Choose Affect the Answers You Get. 2008. Comparative Political Studies 41 (11): 1439-1465. [LINK] [PDF] || Supplemental Materials [PDF] || Replication Data [TXT] || Replication Data Codebook [TXT]

Electoral Rules and the Size of the Prize: How Political Institutions Shape Presidential Party Systems (with Allen Hicken). 2008. Journal of Politics 70 (4): 1109-1127. [LINK] [PDF] || Supplemental Materials [PDF] || Replication Data [TXT] [XLS] || Replication Data Codebook [PDF]

WhatIf: R Software for Evaluating Counterfactuals (with Gary King and Langche Zeng). 2006. Journal of Statistical Software 15 (4). [LINK] [PDF]

Work in Progress

Books:
Changing Societies, Changing Party Systems.

Articles:
Are All Presidents Created Equal? Presidential Powers and the Shadow of Presidential Elections (with Allen Hicken) [PDF] || Supplemental Materials [PDF]

Legislative Policy-Making Authority, the Number of Parties and Party System Aggregation (with Allen Hicken) [PDF]

Are Preceding Presidential Elections the Only Presidential Elections that Shape Legislative Electoral Coordination?

Dissertation

Social Cleavages, Political Institutions, and Party Systems: Putting Preferences Back into the Fundamental Equation of Politics [PDF]

Miscellaneous

The WhatIf Website (with Gary King and Langche Zeng) [LINK]

Complete Israeli Election Results, 1949-2009 (with Nir Atmor). [XLS] Contribution to the Constituency Level Elections Archive (CLEA) at the University of Michigan, Ann Arbor. [LINK]