Does a Judge's Party of Appointment or Gender Matter to Case Outcomes? An Empirical Study of the Court of Appeal for Ontario (Canada)

Abstract:     
A recent study by Cass Sunstein identified ideological differences in the votes cast by judges on the United States Court of Appeals in certain types of cases. He also found that these patterns varied depending on the ideology of an appellate judge's co-panelists. In this study, we undertake a similar examination of the busiest appellate court in Canada, the Court of Appeal for Ontario. This study collects data on the votes cast by individual judges on that court in every reported decision between 1990 and 2003. Each case was coded by type, for example "criminal law", "constitutional law", or "private law". In addition, the votes cast by individual judges in each category were tracked based on variables such as the type of litigant, the political party that appointed the judge, and the judge's gender.

This study reveals that, at least in certain categories of cases, both party of appointment and gender are statistically significant in explaining case outcomes. Between these two variables, gender actually appears to be the stronger determinant of outcome in certain types of cases. While these findings are cause for concern, this study also points toward a simple solution. Diversity in the composition of appeal panels both from the standpoint of gender and party of appointment dampened the statistical influence of either variable. In other words, in the case of gender, a single judge on a panel who is of the opposite sex from the others, or in the case of political party, a single judge appointed by a different political party, is sufficient to eliminate the potential distorting influence of either variable. This finding suggests a need to reform how appeal panels are currently assembled in order to ensure political and gender diversity, so as to minimize concerns about the potential for bias.

Keywords: Empirical Law & Economics, Judicial Process

JEL Classifications: K00, K41

Accepted Paper Series