THE DATA FOR MARIJUANA USE AND THEFT INDICATE THAT NO RELATIONSHIP EXISTS BETWEEN PERCEPTIONS OF SEVERE PUNISHMENT AND ADMITTED CRIMINALITY. PERCEIVED CERTAINTY OF PUNISHMENT APPEARS TO BE RELATED TO ADMITTED CRIMINALITY. HOWEVER, THE STRENGTH OF THIS RELATIONSHIP VARIES BY CRIME AND BY THE INDEX OF CERTAINTY EMPLOYED. FOR EACH OF THE CERTAINTY INDICES, MARIJUANA USE SEEMS MORE RELATED THAN ADMITTED THEFT ACTIVITY TO PERCEPTIONS OF THE CERTAINTY OF PUNISHMENT. THE STRONGEST SUPPORT IS FOUND IN THE PERCEPTION THAT ONE'S OWN CRIMINALITY IS LIKELY TO RESULT IN AN ARREST. THE NEXT GREATEST SUPPORT APPEARS TO COME FROM THE PERCEPTION THAT ONE'S OWN CRIMINALITY IS LIKELY TO EVENTUATE IN THE MAXIMUM ALLOWABLE PENALTY FOR A SPECIFIC CRIME. (AUTHOR ABSTRACT)