RecruitingBehavioural interventionUsing Novel Behavioral Economic Measures to Characterize Dual Marijuana and Tobacco Use in Young AdultsThe multi session experimental study aims to determine dual use patterns of marijuana and tobacco by assessing the impact of price and availability of marijuana and tobacco using a cross price elasticity of demand task. The study will recruit 120 non-treatment seeking emerging young adults (18-25 years) who smoke marijuana and tobacco.