Published online by Cambridge University Press: 26 January 2016
What explains the electoral staying power of many Japanese interest groups in the wake of electoral reform? Electoral explanations provide part of the answer; candidates in elections to both houses of the Diet continue to face incentives—many of them unintended—to court the organized vote. But missing from such accounts is an explanation of why economically noncompetitive groups provide the bulk of such support. The primary reason for this, I argue, is organization. As a result of their historical linkages to the bureaucracy, many interests developed hierarchical, national organizational structures that enabled them to carry out a variety of vote-gathering functions that the parties had trouble performing themselves. Although electoral reform and long-term demographic trends have weakened the electoral influence of interest groups, these organizational complementarities between groups and the parties continue to matter in Japanese elections—including under conditions of two-party competition. To illustrate these points, I trace the evolution of interest group politics from the era of LDP dominance through the rise of two-party competition and the LDP's recent return to power, using postmasters associations and agricultural cooperatives as case studies.