Adaptive parties: party strategic capacity under Japanese SNTV

What shapes a party’s ability to act strategically? We address this question by examining nomination behavior under Japanese SNTV/MMD, a system offering data that overcome the shortcomings of measurement error and static analysis that plague empirical research on party strategy. We run a series of generalized event counts (GEC) to model the number of candidates each Japanese political camp nominated at the district level in eleven different elections. The number of nominees is a highly strategic decision under SNTV, resulting in a statistical anomaly: an underdispersed event count variable. Based on the GEC results, our principal substantive finding is that parties are not as strategically capable as the existing scholarly literature claims. Even when parties are willing to act as a unified strategic group, informational uncertainty may leave them unable to do so. We also find that, despite factors that should have mitigated against strategic capacity, both ruling and opposition parties in Japan frequently responded to one another by seeking to take advantage of their opponents’ strategic errors.