The numbers in Tables 5 and 6 imply that defection was not profitable for the defector in the SP condition: the defector's average income was reduced by 38.4 = 25.2 points, whereas the gain from defection was only 10, generating a net loss of 15.2 points. Therefore, cooperation was the better choice from a purely monetary viewpoint.

Ernst Fehr, Third-Party Punishment and …, loc. 117