Although probably irrelevant to the contents of this post, a few solicited
comments:

1. Rational choice theory is not a theory of preferences, but a theory of strategic interaction, meaning the results of interaction among rational individuals. Hence, it is never meant to explain things such as "PM Noda's single-minded devotion to pushing the unpopular consumption tax hike."

2. The standard notion of elected official preference is the "trinity"
theory of reelection, office,and policy, which dates back at least as far as the early Harvard political scientist V.O. Key. It's closest rival is the reelection-only view, most elegantly stated by David Mayhew. Most recent empirical studies of U.S. Lawmakers corroborate the "trinity" theory, implying that elected officials and by extension political parties face a fundamental conflict of interests (or cognitive dissonance, if you wish).

3. What rational choice can explain is the current interaction between the party leaders, which is basically a model of crisis bargaining. In this case, the responses of the leader's party contingents as well as the rival party's members matter and it is basically an informational game. The Japanese media almost abuses the term "chicken game" to describe the current situation, well, that is rational choice theory.

For what it's worth.

Nobuhiro Hiwatari
Institute of Social Sciences