Effects of varying the "openness" of an economy on responding for cigarettes.

The extent to which drugs are consumed may be related to whether they are available in a closed or open economy. This study examined the effects of the "openness" of an economy on responding for cigarettes during a computer task and cigarettes earned. Using a within-subjects design, openness was manipulated by varying the number of free (unearned) cigarettes available to subjects during a 6h post-task period. No free cigarettes were available during the "closed" economy session; 5 or 10 free cigarettes were available during the two open economy sessions. Subjects performed a concurrent random-ratio (RR) schedule task to earn points redeemable for cigarettes or money. The cigarette schedule varied within a session from RR1.3 to RR16. Throughout each session, money was concurrently available under an RR4 schedule. As the number of free cigarettes increased, fewer responses were made for cigarettes and fewer cigarettes were earned. A behavioral economic analysis of cigarette demand curves revealed that demand for cigarettes was equally elastic when subjects received 5 or 10 free cigarettes, but less elastic when they received no free cigarettes. We conclude that whether an economy is closed or open affects drug (cigarette) consumption in humans, but the degree of openness has limited effects.