A comparison of measures of relative reinforcing efficacy and behavioral economics: cigarettes and money in smokers

In this experiment, we compared behavioral economic measures and measures o f the relative reinforcing efficacy of cigarettes and money between-partici pants. The experiment proceeded in two phases. In the first phase, money an d cigarettes were available on separate progressive ratio (PR) schedules wh en they were solely available. The response requirement for the PR schedule increased across sessions, rather than within a session. In the second pha se, money and cigarettes were made concurrently available at some of the re sponse requirements employed during the PR schedule. Measures of (1) PR bre akpoint, (2) peak response rate, (3) preference, (4) elasticity and (5) P-m ax (the price at which the greatest amount of responding occurs) were compa red within participant. Across the PR- and concurrent-schedule conditions, the three measures of reinforcing efficacy (breakpoint, response rate and p reference) yielded an inconsistent assessment of the relative reinforcing e fficacy of money and cigarettes. The reinforcer that resulted in greater pe ak response rates varied across subjects, while PR breakpoint was higher fo r cigarettes in all participants. Further, in concurrent schedules, prefere nces for cigarettes or money reversed across the response requirements. Beh avioral economic analyses suggest that P-max and elasticity are related to PR breakpoint, and that preference can be predicted from a comparison of th e demand curves under single-schedule conditions. Implications for the conc ept of reinforcing efficacy are discussed. (C) 1999 Lippincott Williams & W ilkins.