The note included in the envelope described the money's owner as either male or female, young or old, rich or poor, or an association representative or an individual. The same envelopes also contained a one pound note. One hundred sixty letters were left available for theft on 31 days over a 9 month period. The nonreturn rate was significantly higher when cash was included in the envelope than when it was not. Sex of the victim was the only measured factor which significantly affected the incidence of theft. Subjects were more likely to steal from male victims, especially when the subject was old or rich. The sex of the subjects did not significantly affect their probability for committing theft, nor did the presence or absence of companions. Subjects' age and style of dress were positively related to the theft incidence. Young, casually dressed subjects were more likely to steal than older, more formally dressed ones. Subjects who concealed the envelope upon picking it up were more likely to steal it than those who did not. Theft was not related to the area of the drop, character of the drop site, the number of people in sight when the envelope was discovered, the number of people passing before the letter was picked up, or the number of companions with the subject. It was concluded that stealing depended partly on the individual and partly on situational factors. Tables and a list of 15 references are included.