The State of Malapportionment in the World: One Person, One Vote?

Abstract

Malapportionment — the discrepancy between the share of legislative seats and the share of the population, or electorates, 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 in several ways. Despite its importance, relatively little research exists on this topic. This study attempts to fill this gap by highlighting two aspects. First, we provide the most extensive dataset of malapportionment currently available, accumulating data from 83 countries and 216 elections. This dataset compares the following measures of malapportionment: (1) the Loosemore–Hanby index-based measure provided in Samuels and Snyder (2001), called MALSS, in this study, (2) the ratio of largest-to-smallest districts, or the max–min ratio (MALMAXMIN), and (3) MALGINI, which employs the calculation method of the Gini index. Our analyses show that MALSS and MALGINI are highly correlated, but MALMAXMIN yields a highly different value in comparison with MALSS and MALGINI. Second, our regression analyses, using a new database we developed, show that most of the factors that previously argued to influence the degree of malapportionment are not robustly significant, except for the single-member district (SMD) electoral formula.