 BMIs are associated with reductions in alcohol consumption and related problems, but effect sizes are generally small. One BMI trial indicated that behavioral economic variables such as low levels of proportionate substance-free reinforcement and inelastic demand for alcohol predicted poor intervention response, and that participants who successfully reduced their drinking increased their participation in academic and other substance-free activities. A subsequent NIAAA R21 developed a substance-free activity session SFAS supplement to traditional alcohol BMIs that attempted to increase engagement in constructive alternatives to drinking by enhancing the salience of delayed rewards academic and career success and the patterns of behavior academic engagement leading to these outcomes. This study indicated that a two session alcohol BMI SFAS preventive intervention resulted in significantly greater reductions in alcohol problems relative to a two session alcohol BMI Relaxation active control condition. The BMI SFAS was also associated with significantly greater reductions in heavy drinking for participants with lower levels of substance-free reinforcement at baseline. This was the first controlled study to demonstrate that a supplement to traditional BMIs can improve outcomes. The current study will extend these promising pilot results by a increasing the efficacy of the behavioral economic SFAS by including booster contact, b increasing power and generalizability by recruiting 425 students from two universities and including a no-treatment control group, c measuring drinking, as well as behavioral economic mechanisms as mediators and moderators of intervention outcomes delay discounting, alcohol reinforcing efficacy, substance-free reinforcement at 5 time points over a sixteen month period, and d evaluating the economic costs and benefits associated with the SFAS. The goals of the SFAS - increasing student engagement in academic, campus, and career-related activities- are consistent with the priorities of most colleges. 