Abstract
Since the works of Downs and Black on spatial models of competition between political actors, political scientists have invented various methods for estimating policy positions using different sources of information. This article conceptualizes the variety of methods for estimating policy positions as a multi-layer structure of policy positions, and proposes that this concept could be used as a framework to analyze the consistency and change of representation through the political process. Based on this framework, this article examines the relationship between political parties and the inconsistency of legislator's behavior. I then used three measures to estimate the policy positions of Japanese legislators on the constitutional revision issue from three sources; an elite survey, campaign pledge, and Diet Record. Moreover, I analyze the distance between the three policy positions. The result demonstrates that the extent of inconsistency in legislator's behavior differs from political parties. In particular, it is possible that each party's electoral strategy restricts the content of their member's campaign pledges.
