We use a pseudo‐panel data approach to analyze the relationship between the consumptions of cigarettes, alcohol, and coffee in a rational addiction framework. We find that while cigarette and coffee demands fit well with the rational addiction model, alcohol demand conforms to a model with inventory effects. The results suggest that alcohol consumption increases the marginal utility derived from consumption of cigarettes. Increasing alcohol prices would decrease not only the consumption of alcohol, but also the consumption of cigarettes. On the other hand, increasing cigarette prices do not have the same effect on consumption of alcohol. The cross‐price elasticity of coffee with respect to cigarette price is positive and significant which suggests that coffee substitutes for cigarettes when cigarette prices increase. The cross‐price elasticity of alcohol with respect to coffee price is found to be negative and significant. On the other hand, Morishima elasticities of substitution indicate that cigarette, alcohol and coffee substitute each other along the indifference curve when relative prices change.