| The electoral system Japan has used since shortly after World War II has two distinguishing characteristics: unequal apportionment and multi-member districts with Single Non-Transferable Voting (SNTV) rule. In this voting rule voters can write only one name, though the districts choose more than one representative. In this dissertation we evaluate these two characteristics.;The most common election rules used in the world are either single-member districts with a plurality winner or a proportional representation system with a party-decided list of candidates. Many Japanese consider one or the other of these common systems ideal and criticize multi-member districts with SNTV.;In Chapter II, using a non-cooperative game theoretical model, we show that single-member districts with a plurality system do not necessarily result in a two-party system. Without a guarantee of systematic political alternation, multi-member districts with SNTV may be superior to single-member districts with a plurality system. The multi-party system that results from SNTV generates better proportionality of representation than single-member districts with a plurality winner.;In Chapter III, using a cooperative game theoretical model, we show that having multi-member districts with SNTV makes government formation similar to that in a proportional representation system. Since the traditional Japanese system's proportionality is similar to that of the proportional representation system, and the mechanism of its final stage, government formation, is almost the same, multi-member districts with SNTV might be better than the other most common election rule, a proportional representation system with a party-decided list of candidates. This is because SNTV makes politicians more sensitive to the voters than to the party.;In Chapter IV, using a model of "voting with one's feet", we show that changing the apportionment of representatives in Japan, where there is now misapportionment, improves the welfare of the people, and, in equilibrium, even those people in the district that lose their own representation. Therefore unequal apportionment works against both fairness and efficiency. Many Japanese favor the existing misapportionment, but considerations of both fairness and efficiency argue for change. |
