三輪 洋文

In Japan, the gender gap in attendance at 4-year universities is narrowing, yet significantly fewer women apply to selective colleges. A growing body of literature suggests that gendered expectations of educational returns and cultural stereotypes, most compellingly reflected in parental influence, are pivotal in shaping children’s college choices. However, the capacity to make causal claims remains limited in existing research, as observed gendered preferences among parents may merely echo earlier educational investments made before college applications. This study advances the field by leveraging a survey experiment approach. Our conjoint experiment, where respondents evaluate hypothetical college choices of fictitious children, yields several key findings. First, responses show no difference when the children, regardless of their gender, opt for selective colleges. Second, the respondents who expect higher returns from college education for men than for women tend to favor their fictitious son’s selective college applications. Third, fictitious daughters’ college choices are rated more favorably when they conform to societal gender stereotypes. These findings underscore the potential influence of recent admissions reforms in Japanese universities, including explicit quotas for female applicants, aimed at increasing their enrollment.

Japan is an intriguing case in the literature of judicial independence because of the Liberal Democratic Party's (LDP) long-lasting one-party dominance in government—which, in theory, leads to low independence. Although scholars have found plentiful anecdotal observations implying the LDP's judicial control, quantitative evidence remains scarce. Focusing on the Supreme Court as the first step, this study provides a new dataset on justices' ideal points through an extensive compilation of justices' voting data and application of the dynamic item response theory model. I validate the estimates' interpretability as ideological positions. The results present several novel findings: justices with a career-judge background are relatively conservative; the Chief Justice tends to be particularly conservative; the conservative camp has tended to hold on to a court majority since the 1960s; and the government's partisanship, to some degree, influences appointed justices' positions. These results reinforce scholars' views that Japan's court leans conservatively and aligns with the LDP, with implications for judicial independence in Japan.

Recent studies in democratic countries suggest that voters generally prefer candidates with specific personal attributes, such as being female and young. However, some of these patterns cannot necessarily be explained by voters’ expectations of candidates’ competence. Building on a growing body of literature that addresses populist attitudes as an important factor influencing voters’ political preferences, this study hypothesizes that candidates’ personal attributes shape voters’ perceptions of their populist attitudes and that such perceptions mediate the relationship between personal attributes and voter preferences. A conjoint experiment conducted in Japan showed that several personal attributes substantially influenced candidates’ perceived anti-elitism and people-centrism. An additional experiment to disentangle causal mechanisms suggested that, albeit inconclusive, young candidates were more likely to be preferred because of voters’ expectations of their populist tendencies. Methodologically, this study illustrates advancements in the conjoint experiment design to elucidate causal mechanisms, with a careful discussion of necessary assumptions.

In bicameral legislatures, gender representation varies significantly between chambers. Historically, Japan's upper house has maintained a proportion of women twice that of the lower house. However, electoral systems alone cannot fully explain this disparity. We argue that seemingly gender‐neutral legislative institutions influence both voting behavior and candidates' willingness to run, contributing to significant disparities in gender representation in bicameral legislatures. To test this argument, we conduct two survey experiments exploring the underlying mechanisms from the perspectives of voters and candidates. Our findings suggest that informing voters about the upper house's subordinate role increases support for female candidates in upper house elections. Furthermore, women display a greater willingness to pursue office when assured of job security in the upper house, while men exhibit less interest when made aware of its limited authority to appoint the prime minister. This study enhances our current understanding of the effects of asymmetrical institutions between chambers from a gender perspective.

We add new insights to the party theory of parliamentary debate proposed in Proksch and Slapin’s The Politics of Parliamentary Debate by combining a quantitative replication analysis of floor speeches with a qualitative explanation of the endogenous transformation of two institutions mediating elections and parliamentary speech in the Japanese Diet. Although the House of Representatives in Japan used a single non-transferable vote system with particularly strong personal vote-seeking incentives, our analysis based on a new dataset shows that, contrary to the theory’s predictions, the pattern of speech activities among party leaders and backbenchers is close to that of Germany, which has a party-centered proportional representation system. Such seemingly contradictory results, however, can be consistently understood within the scope of the theory if we consider the patterns of endogenous change in the parliamentary system and party organization. These results highlight the potential for further development of the theory.