Analyzing Roll Calls with Perfect Spatial Voting: France 1946–1958


  • Howard Rosenthal,

  • Erik Voeten

  • This work was supported by National Science Foundation (NSF) grant #973053. Any opinions, findings, and conclusions or recommendations in this work are those of the authors and do not necessarily reflect the views of the NSF. We thank three anonymous referees, discussants, and participants at the 2001 annual meeting of the American Political Science Association in San Francisco, the annual meeting of the Public Choice Society, San Diego, CA, and seminar participants at Berkeley, particularly Robert Powell, for comments. A very special thanks to Keith Poole for his counsel and programs.

Howard Rosenthal is Roger Williams Straus Professor of Social Sciences, Professor of Politics, Princeton University, Corwin 038, Princeton NJ, 08544 and Distinguished Visiting Professor of Economics and Politics, Department of Economics, Brown University, Box B, 64 Waterman Street, Providence, RI 02912 ( Erik Voeten (corresponding author) is Assistant Professor of Political Science and International Affairs, The George Washington University, Funger Hall 514, 2201 G Street, NW, Washington DC 20052 (


A recent methodological advance in legislative roll-call analysis is especially relevant to the study of legislative behavior outside the setting of the United States Congress. We argue that Poole's (2000) optimal classification method for roll-call analysis is preferable to parametric methods for studying many legislatures. This is because the nature of party discipline, near-perfect spatial voting, and parliamentary institutions that provides incentives for strategic behavior lead to severe violations of the error assumptions underlying parametric methods. The robustness of the nonparametric method to the stochastic nature of the data makes it an ideal candidate for studying strategic behavior in legislatures. We illustrate these points with an analysis of data from the French Fourth Republic (1946–1958).