Policy Positions in Mixed Member Electoral Systems: Evidence from Japan



Do mixed member electoral systems provide the ``best of both worlds''? We examine whether candidates in the proportional representation (PR) tier of these systems take policy stances closer to their party's position while candidates in the single member district (SMD) tier adopt policy positions to appeal to their districts preferences. We exploit a comprehensive panel survey of all candidates for the Japanese Upper and Lower House elections between 2003 and 2010 and estimate the policy positions of each candidate over time using Bayesian item response theory model. Our analysis suggests that candidates' policy positions vary substantially within parties. In addition, the two major parties appear to converge in the economic policy dimension during this period. In general, we find limited evidence consistent with the ``best of both worlds'' hypothesis. In the economic policy dimension, there is tentative evidence that Lower House SMD candidates are responding to their districts' preferences while PR candidates are closer to the position of the median party member. In the main foreign/security policy dimension, however, SMD candidates are not particularly responsive to their districts' preferences. (Last revised, August 2011)

© Kosuke Imai
 Last modified: Tue Sep 20 16:32:23 EDT 2011