The present study had two aims : ( 1 ) compare standard care ( SC ) for smoking ( four weeks of brief counseling and monitoring ) to SC plus prize-based contingency management ( CM ) , involving the chance to earn prizes on days with demonstrated smoking abstinence ( carbon monoxide ( CO ) 6 ppm ) ; and ( 2 ) compare the relative efficacy of two prize reinforcement schedules-one a traditional CM schedule , and the second an early enhanced CM schedule providing greater reinforcement magnitude in the initial week of treatment but equal overall reinforcement .