Christine Boyd and Lee Epstein -- Female Justices Make a Difference

By Christina L. Boyd and Lee Epstein
Sunday, May 3, 2009

When Sandra Day O'Connor retired from the U.S. Supreme Court in 2005, national polls suggested that the public overwhelmingly supported replacing her with a female juror. O'Connor seemed to agree. "He's good in every way, except he's not a woman" is what she had to say about the nomination of John G. Roberts Jr.

Now, Justice David H. Souter is set to retire from the court, and President Obama is already facing similar pressure. Who might take Souter's place? We're already being introduced to Sonia Sotomayor, Elena Kagan and Pamela Karlan -- all very accomplished individuals who happen to possess the one qualification that many commentators and court-watchers seem to agree is the most important this time around: They are women.

Some of the pressure comes from those who believe that the membership of our courts should reflect the makeup of our society. More than half the U.S. population is female. Nearly one-third of all U.S. lawyers are women. Approximately 30 percent of the judges serving on the lower federal courts are women.

But a diverse Supreme Court isn't just about a bench that looks like America. This is about jurisprudence, too. In research that we conducted with our colleague Andrew D. Martin, we studied the votes of federal court of appeals judges in many areas of the law, from environmental cases to capital punishment and sex discrimination. For the most part, we found no difference in the voting patterns of male and female judges, except when it comes to sex discrimination cases. There, we found that female judges are approximately 10 percent more likely to rule in favor of the party bringing the discrimination claim. We also found that the presence of a female judge causes male judges to vote differently. When male and female judges serve together to decide a sex discrimination case, the male judges are nearly 15 percent more likely to rule in favor of the party alleging discrimination than when they sit with male judges only.

This holds true even after we account for judges' ideological leanings. If Obama is considering two fairly moderate people, one a woman and the other a man, we would expect the woman to cast more liberal votes in sex discrimination cases. The same would be true if the president were considering two very liberal candidates, again, one a man and one a woman.

The retirement of the liberal-leaning Souter may not give the president a chance to move the court significantly to the left. But it does let him make a different shift. If he does choose a woman to fill Souter's seat, he could have a major impact on an area of law that's important to many Americans -- women and men alike.

Christina L. Boyd is a PhD candidate in political science at Washington University in St. Louis. Lee Epstein is a professor of law at Northwestern University.

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