The authors’ analysis persuasively suggests the prevalence of bribery in the sumo wrestling world. On the surface, one would expect an 8-6 wrestler to beat a 7-7 wrestler slightly more than half of the time; in reality, the 7-7 wrestler wins considerably more often. Notice that the authors do not (and, in fact, cannot) pinpoint
which wrestlers do and don’t take bribes. It would be very difficult to analyze specific sumo matches and decide which ones are legitimate and which ones are rigged. By studying the sport of sumo wrestling as a whole, however, economists can estimate that a significant number of wrestlers cheat, without having a very good idea of which wrestlers they are.