A recent paper by Stephen Choi (NYU), Mitu Gulati (Duke), and Eric Posner (Chicago) will surely interest judicial decisionmaking scholars (and others). In Professionals or Politicians: The Uncertain Empirical Case for an Elected Rather than Appointed Judiciary, the authors set out to test the conventional wisdom that suggests "appointed judges are superior to elected judges because appointed judges are less vulnerable to political pressure." Drawing on a dataset of state high court opinions, the authors "construct objective measures for three aspects of judicial performance: effort, skill and independence. The measures permit a test of the relationship between performance and the four primary methods of state high court judge selection: partisan election, non-partisan election, merit plan, and appointment." A brief description of the results from their study follows.
"... results do not show appointed judges performing at a higher level than their elected counterparts. Appointed judges write higher quality opinions than elected judges do, but elected judges write many more opinions, and the evidence suggests that the large quantity difference makes up for the small quality difference. In addition, elected judges do not appear less independent than appointed judges. The results suggest that elected judges are more focused on providing service to the voters (that is, they behave like politicians), whereas appointed judges are more focused on their long-term legacy as creators of precedent (that is, they behave like professionals)."