The Effects of Alcohol Consumption on Restaurant Tipping.

Two explanations for the effects of alcohol on prosocial behavior-that is, mood enhancement and cognitive impairment-suggest that restaurant diners should tip more when they have consumed alcohol than when they have not. However, previous attempts to find a relationship between percent tip and alcohol consumption have failed. This failure may be due to statistical problems associated with using percent tip as a measure of tipping. This article reports a study that uses as a dependent variable residuals from a regression of bill size on tip amount. The results of this study indicate that alcohol consumption is positively related to tipping.