Untangling the Causal Effects of Sex on Judging  

Christina L. Boyd, Lee Epstein, and Andrew D. Martin. 2010 "Untangling the Causal Effects of Sex on Judging." American Journal of Political Science. 54(2): 389-411.

Winner: 2008 Midwest Political Science Association Pi Sigma Alpha Award

Discussed in: April 2009 Newsweek article ("Women: Truly the Fairer Sex"); May 2009 Washington Post op-ed ("When Women Rule, It Makes a Difference")
; June 2009 New York Times article ("Debate on Whether Female Judges Decide Differently Arises Anew"); June 2009 Washington Post article ("Court Watch: Wise Women, Impacting the Courts?"); July 2009 National Journal Magazine article ("Do Gender And Race Mean Greater Empathy?"); Interviewed about for "Who Should Be Next on the US Supreme Court?" on NPR affiliate program To The Point hosted by Warren Olney.


We enter the debate over the role of sex in judging by addressing the two primary theoretical and empirical questions it raises: whether and in what ways male and female judges decide cases distinctly---"individual effects"---and whether and in what ways serving with a female judge causes males to behave differently---"panel effects." While we attend to the dominant theoretical extant accounts of why we might expect to observe either or both effects, we do not use the predominant statistical tools to assess them. Instead, we deploy a more appropriate methodology---semi-parametric matching, which follows from a formal framework for causal inference.  Applying matching methods to thirteen areas of law, we observe consistent effects in only one---sex discrimination. For these disputes, the probability of a judge deciding in favor of the party alleging discrimination decreases by about 10 percentage points when the judge is a male. Likewise, when a woman serves on a panel with men, the men are significantly more likely to rule in favor of the rights litigant. These results are consistent with an informational account of gendered judging and are inconsistent with several others.

Further project information and data available on Epstein's webpage.