Hypothetical changes in daily cocaine purchasing (U.S. dollars) as a function of the likelihood of arrest (0.25–8 times normal risk) when buying cocaine. As shown in this demand curve, the highest-income quartile (Q4) reported they would purchase significantly more cocaine than the low-income quartile (Q1) at most arrest probabilities (asterisks). Overall, there was a main effect of income quartile on expected cocaine purchasing (i.e., a shift in demand intensity), however, cocaine purchasing did not differentially decrease across groups as arrest probability increased (i.e., no group differences in price-elasticity).