"Abstract: To study the determinants of judicial productivity and speed (measured by published opinions), I examine all 348 trial-court civil medical malpractice opinions published in Japan between 1995 and 2004. For comparative purposes, I add 120 randomly selected civil judgments from the same period. The data cover 706 judges (about a third of the Japanese bench). I find: (A) Productivity correlates with apparent intellectual ability and effort. The judges who attended the most selective universities, who passed the bar exam most quickly, and who were chosen by the courts for an elite career track publish the most opinions. (B) Adjudicatory speed correlates with apparent ability and effort too, but institutional experience counts as well. As the courts acquired increasing experience with malpractice cases, the pace of adjudication quickened"--John M. Olin Center for Law, Economics, and Business web site.