Our findings do not bear directly on the empirical literature that suggests that women and men decide cases differently when those cases involve issues of particular concern to women—for example, sex discrimination or family law cases. But we did wonder whether the judicial opinions of female judges on these issues might receive more citations because other judges would regard the women as expert. However, we found no difference in this respect.
How could it be that the female judges chosen from a smaller pool, and with less impressive credentials, perform as well as male judges? There are two possible answers. (A third, that our measures of judicial quality are not any good, we prefer to ignore!)
First possibility: Sotomayor and Lithwick may be correct. Women might be better judges than men, and that would explain why less experienced women perform just as well as more experienced men—with women's "life experience," in effect, making up for their more limited legal experience. This theory implies that women should outperform men of equal experience. And, in fact, as we've mentioned, our data show that, controlling for experience, women do outperform men on one of the three measures—independence. A woman who'd gone to Harvard and moved to the bench after 20 years of experience in a law firm would be a somewhat more independent judge than a man with the same professional background—that is, more likely to publicly disagree with a judge of her party. One might conjecture that women develop thicker hides in legal practice or that men with thinner hides are more likely to flee the rigors of private practice and take refuge in lower-paying judgeships. But that part is speculation.
The second potential explanation for our findings: It might be that presidents (and governors and others who select judges) look for characteristics other than elite education, legal experience, and similar markers. Perhaps they do this because such factors only poorly predict a person's success as a judge. Presidents and governors may have a rough sense of a threshold for a judicial candidate, one that leaves them with a large group from which to choose on the basis of other characteristics—for example, party loyalty, or personal reputation, or other intangibles. If this is so, a politician who chooses a woman rather than a man does not sacrifice quality. This might explain why female judges tend to be more independent than male judges: With a deeper pool of men to choose from, perhaps politicians select men who are proven partisan loyalists rather than the men with the most talent.
Whatever the reason, our basic point is this: The fact that female judges are selected from a shallower pool of talent does not imply that they are worse judges than men. In fact, the evidence suggests that they are at least as good as male judges, perhaps better. When she sat on the 2nd U.S. Circuit Court of Appeals, Justice Sotomayor ranked among the most cited federal appellate judges in the country. Bring on the women!