Malapportionment―the discrepancy between the share of legislative seats and the share of the population within a given geographical unit―violates one of the fundamental principles of democratic government, namely, one person, one vote. It also leads to undesirable governance results in many ways. Despite its importance, however, we know little about the causes of malapportionment. This paper examines this question with a focus on the role of the judiciary. I hypothesize that countries with higher de facto judicial independence and higher judicial activism tend to have lower levels of malapportionment. The basic logic behind this idea is the following: in countries where the judiciary exercises effective checks on violations of people's fundamental rights, the ruling elites are more likely to amend the electoral laws to reduce malapportionment and/or to avoid committing such violations in the first place. Cross-national statistical analyses, as well as case studies of the US and France, are provided. Both approaches provide evidence for these claims. Another noteworthy finding is that when the degree of judicial independence is controlled for, the effects of having a single-member district system lose their significance.

論説