Also in today’s Washington Post, political scientists Christina L. Boyd and Lee Epstein put in a plug for replacing Justice Souter with a woman. But their case for this is a strangely narrow one. Summarizing research they have conducted with Andrew D. Martin, Boyd and Epstein say

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.

Actually, the paper Boyd and Epstein did with Martin, to which they link, did not “stud[y] the votes of federal court of appeals judges in many areas of the law.” It studied only sex discrimination cases under Title VII, and the authors explicitly remark that “it seems worthwhile to consider several other areas of the law” because they didn’t. Perhaps there is some other study the three of them have conducted, but the one they link here does not do what they claim it did in their Post article.

Why Boyd and Epstein would claim more for their study than it did escapes me, since a more modest claim would help their case more. “We found a difference in sex discrimination cases; let’s go look for differences elsewhere” is a lot more compelling than “We looked everywhere and found only a (small) difference in sex discrimination cases.” After all, why should anyone attach so much importance to Title VII cases as to make a choice of a Supreme Court justice’s sex turn on it?

And of course, we wouldn’t have any idea whether Title VII cases were decided more justly or more unjustly, from knowing only that they were decided more or less often for the claimants. Would we?

UPDATE: A reader points me to another paper by Boyd et al. in which the effect of women’s participation on appellate courts was compared across various areas of the law. So Boyd and Epstein do, after all, have just as uncompellingly narrow a case for women judges as they say they did. But why didn’t their Post article point to the research results they were claiming? And, of course, my final point above stands quite unaffected.