Japan uses simple plurality elections with multi-member districts to elect its lower house. This system tends to produce competition among n + 1 candidates per district. This ‘law of simple plurality elections’ is a structural generalization akin to Duverger's Law. Evidence from Japan also indicates that the causal mechanism behind this ‘law’ is not strategic voting, although strategic voting occurs, but elite coalition building. It is further argued that the connection between structure and behaviour is learning and not rationality. Equilibria are reached slowly through trial and error processes. Once reached, the equilibrium is unstable because parties and candidates try to change it. Even without rational actors and stable equilibria, however, this structural generalization accurately describes the dynamics of electoral competition at the district level in Japan.

When do politicians resort to corrupt practices? This article distinguishes between two types of corruption by politicians: illegal acts for material gain (looting) and illegal acts for electoral gain (cheating). Looting generally involves a politician “selling” influence while cheating involves a politician “buying” votes. Individual‐level analyses of new data on financial scandals and election law violations in Japan show that the determinants of cheating differ from the determinants of looting. Most notably, political experience and electoral security increase the probability of looting, but electoral insecurity combined with intraparty competition increases the probability of cheating.

Examining the 1993 split of the Liberal Democratic Party (LDP) in Japan offers an opportunity to gain greater insight into the impact of the various incentives that influence the behaviour of politicians. Surprisingly, previous analyses of the LDP split have been able to demonstrate only weak evidence of any electoral connection driving politicians' decisions. However, by also examining the role of policy preferences (support for reform) and utilizing interaction terms, our analysis takes into account the fact that politicians at different stages in their careers and facing different sorts of electorates respond to electoral factors in very different ways. Our findings thus confirm the importance of the electoral connection. We are also able to add that a variety of other incentives also shape political behaviour and that politicians do not necessarily all respond to similar stimuli in the same way.

In 1993, Italy adopted an electoral system based largely on single-member districts (SMD) based, at least in part, on the hope that SMDs would lead to a two-party system and alternation in government. That idea is known in political science as Duverger's law. The overwhelming consensus among specialists in Italian politics would appear to be that Duverger's law is not working very well in Italy. I will argue, to the contrary, that Duverger's law is working exactly as should have been expected. Although one may see little evidence of movement toward a two-party system at the national level, between the 1994 and 1996 elections, more than 80% of electoral districts moved closer to bipolar competition between two candidates. A dynamic analysis of electoral districts confirms the powerful operation of Duverger's law in Italy.

The loss of power by the Liberal Democratic Party after more than half a century of dominance was the most obvious outcome of Japan’s 2009 election, but together the 2005 and 2009 elections demonstrate significant shifts in both the foundations of party support and the importance of national swings in support for one party or another. Since 2005, urban-rural differences in the foundations of the leading parties have changed dramatically, and Japan has moved from a system dominated by locally based, individual candidacies toward a two-party system in which both party popularity and personal characteristics influence electoral success or failure.