Drinking Motives Mediate the Relationship Between Reinforcing Efficacy and Alcohol Consumption and Problems

Objective: Several studies have shown that demand curve indices of the reinforcing efficacy of alcohol (i.e., reports of hypothetical alcohol consumption and expenditures across a range of drink prices) are associated with alcohol-related outcomes. A next logical step in this area of research is to examine potential mediators of this direct relationship. It is possible that enhancement and coping drinking motives serve as an intermediary of the reinforcing efficacy–alcohol use relationship, such that higher reinforcing efficacy is associated with increased motivation to drink, which is then associated with greater alcohol use and problems. Method: Data were collected from 215 college undergraduates who reported drinking in the past 30 days. Results: The demand curve reinforcing efficacy indices Omax (maximum alcohol expenditure) and intensity (consumption level when drinks were free) demonstrated the strongest and most consistent associations with alcohol use, problems, and motives. Results from two structural equation models indicated that enhancement and coping motives mediated the relationship between reinforcing efficacy and alcohol use and alcohol-related problems. Conclusions: These results suggest that the motivational effects of the behavioral economic variable reinforcing efficacy on problematic alcohol use are in part mediated by increases in enhancement and coping motives for drinking