Why Is the Japanese Conviction Rate So High?

Eric Bennett Rasmusen, Kelley School of Business, Indiana University
J. Mark Ramseyer, Harvard Law School

Abstract

Conviction rates are high in Japan. Why? We suggest it is because Japanese prosecutors are understaffed. If they can afford to bring only their strongest cases, judges see only the most obviously guilty defendants, and high conviction rates would then follow. Crucially, however, Japanese judges face biased incentives. A judge who acquits a defendant runs significant risks of hurting his career and earns scant hope of positive payoffs. Using data on the careers and published opinions of 321 Japanese judges (all judges who published an opinion on a criminal case in 1976 or 1979), we find skewed incentives to convict. First, a judge who---trying a defendant alone-- acquits the defendant will spend during the next decade an extra year and a half in branch office assignments. Second, a judge who acquits a defendant but finds the acquittal reversed on appeal will spend an extra two years in branch offices. Conversely, a judge who finds a conviction reversed incurs no substantial penalty. Unfortunately for innocent suspects, the absence of an unbiased judiciary also reduces the incentives Japanese prosecutors have to prosecute only the most obviously guilty defendants.