New Electoral System and Party Realignment in Japan

最近，日本众议院选举法发生了重大变化。1994年秋颁布的新法律采用了比例代表制和多数制相结合的“平行制度”或小区制。本研究探讨了两种复杂的投票类型-战略投票和战略平衡-可以在并行系统中运作。研究表明，平行制度包含制度规定（双重候选人和输赢比例），使SMD投票非排他性和可转移到PR部分，从而降低了战略投票的程度，削弱了地方两党制的倾向。当两个以上的有效政党在多数选举中竞争时，具有相似政策和政治倾向的政党应该协调他们的候选人，以防止对立政党在选举中获胜。然而，在并行制度下，各方没有协调的动力。因此，唐斯式的中间派政策压力不会强加给组建新政府的获胜政党。为了向中间政策施压，在平行制度下，拥有两票的温和派选民发挥平衡作用，形成联合政府，以遏制构成新政府核心的多元化政党所追求的政策极端主义。战略平衡的程度与反对派协调失败的程度有关。

Recently, Japan has undergone a major change in the electoral law for the House of Representatives. The new law enacted in fall 1994 has installed a "parallel system" combining proportional representation (PR) and plurality rule or a small district (SMD) system. This study examines two types of sophisticated voting - strategic voting and strategic balancing - that can be operative in the parallel system. It is shown that the parallel system contains institutional provisions (double candidacies and the loser-winner ratio) that make SMD votes nonexclusive and transferable to the PR portion, hence reducing the extent of strategic voting and weakening a tendency toward local two-partism. When more than two effective parties compete in a plurality election, parties holding similar policy and political orientations ought to coordinate their candidates in order to prevent the opposing parties from gaining electoral victory. Under the parallel system, however, the parties have disincentives to coordinate. Thus, Downsian centrist policy pressures are not imposed upon the winning party formulating a new government. In order to pressure it toward centrist policy, moderate voters with two votes under the parallel system perform the acts of balancing so that a coalition government is formed to check policy extremism that is otherwise pursued by a pluralist party constituting the core of a new government. The extent of strategic balancing is found to be associated with the degree of opposition coordination failures.