We explore in this article an institutional foundation of agricultural protectionism in Japan, a country long recognized as resisting international pressures to open up its rice market. Using our qualitative analysis of postwar politics of agricultural protectionism and a simple formal model, we argue that farmers in Japan have stronger incentives to mobilize electoral support for the governing party in multimember district systems than in single-member district systems, because the marginal effects of mobilization on policy benefits are different under these electoral systems. Our empirical findings corroborate this claim and provide implications for the gradual changes in Japan's farm policies occurring after the electoral reform in 1994.
