Under the single non-transferable vote (SNTV), political parties are faced with the strategic problem of matching the number of candidates to their vote total. Running either too many or too few candidates may lose a seat that could otherwise have been won. Many studies have confirmed that Japan's Liberal Democratic Party (LDP) solved this strategic problem relatively well and ran close to the optimal number of candidates. Each of these studies makes the standard unitary actor assumption that the LDP can be understood as if it were a single individual maximizing its total number of seats in the Diet. Even though these unitary actor models have produced an impressive account of LDP nomination policy, I argue for an alternative decentralized model based on candidate strategy. The primary mechanism producing the optimal number of LDP candidates per district is not strategic decision-making by the party headquarters, but competition among strategic candidates. Political parties are organizations and therefore capable of unitary action, but parties are also arenas for competition among factions and candidates. The LDP was not a coherent organization but rather an open arena for candidate competition.
Read full abstract