The Analysis of Roll Call Data from the 18th Korean National Assembly: A Bayesian Approach

We apply a Bayesian estimation procedure to the analysis of roll call voting records on 2,389 bills processed during the 18th Korean National Assembly. The analysis of roll calls yields useful tools for to combining the measurement of legislative preference with the models of legislative behavior. The current Bayesian procedure is extremely exible, applicable to any legislative setting, irrespective of the extremism of the legislator``s voting history or the number of roll calls available for analysis. It can be applied to any legislative settings, providing a useful solution to many statistical problems inherent in the analysis of roll call voting records. We _rst estimate the ideal points of all members of the 18th National Assembly and their con_dence intervals. Subsequently, using the estimated ideal points, we examine the factional disparity within each major party using the estimated ideal points. Our results clearly suggest that there exists a meaningful ideological spectrum within each party. We also show how the Bayesian procedure can easily be extended to accommodate theoretically interesting theoretical models of legislative behavior. More speci_cally, we demonstrate how the estimated posterior probabilities can be used for identifying pivotal legislators.