The argument for ideological diversity on campuses is strengthened by the growing political polarization in society. Political polarization is costly, because citizens then are more likely to dismiss a policy position based on the identity of its supporters and opponents than on the merits. Polarization also makes it harder to reach compromises, and compromises are more often likely to lead to political stability than ideas with a more narrow range of ideological support.
One of the reasons for polarization appears to be that citizens today are more able to live in ideological and partisan cocoons than in the past. They can look at the websites they like and not at those that might challenge their views. Cities and towns also sort themselves out more by political beliefs. Those opposing the predominant views of the their current residence are more likely to move to a more politically hospitable climate. Apparently, Republicans and Democrats even choose to follow different celebrities although they do admire a golfer or two in common.
The most obvious place where citizens should learn to interact with ideological opponents and confront arguments that will challenge their views is the university. But this experience is less likely if the gatekeepers of ideas are almost uniformly of one political persuasion. And so many of our modern universities are ideologically monochromatic.
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.