Six male volunteer subjects were studied for 70 days in a high security hospital setting under a token economic (micro‐economic) system. A 42‐day regimen of free purchase and compulsory marijuana smoking was established, using one gram cigarettes with 8.5 mg Δ‐9THC. This period was preceded and followed by two weeks when marijuana was not available. Subjects were paid only for goods produced. Earnings could be saved or spent to satisfy subjects' needs and consumer desires. All economic transactions were recorded. Data was collected every half hour of each subject's dominant activity. The subjects demanded, and recieved, two wage raises. Introduction of cannabis resulted in lower productivity; reduction of intake raised productivity. A fall in productivity was matched by a fall in time spent working, but not in efficiency. Subjects spent more time resting awake and in entertainment during periods when more marijuana was smoked. Some indications of “amotivational syndrome” were present but no evidence of physiological damage was yielded by clinical medical examinations. Certain relationships between alcohol and rnarijuana were noted.