In a fascinating article, James Phillips has focused on the productivity, citations, and credentials of scholars at the top sixteen law schools. His analysis suggests that conservatives and libertarians are more productive, better cited, and, with one important exception, better credentialed than other scholars. The powerful combination of these findings is thus consistent with the hypothesis that conservatives suffer discrimination in hiring, perhaps particularly in the lateral market when productivity and citation data are very visible. It is as if they are competing in a race with an extra weight on their backs.
I recommend reading the entire article, whose statistics cannot be full summarized nor independently evaluated here. But on what appear to me to be the best specifications, the differences in productivity and citations are not small. Conservatives and libertarians write about three quarters of an article more per year than other professors, both liberals and those of unknown ideology. They garner 13 to 37 more citations than other professors, which is quite a lot given that the average for a year across faculties is only 41 citations. When measured against liberals alone, they are also more productive and more cited, although not by quite as much. They are also better credentialed in matters like membership on law reviews and grade honors in law schools and clerkships, although others are more likely to have a doctorate in another discipline.
Assuming this article is accurate, the normative implication that I draw is that in hiring schools should weigh more objective data, like productivity and citations counts more heavily and take less account of their faculty’s more subjective impression of scholarship.