Self-control is a personality trait that explains undersaving and nonparticipation decisions. We show that self-control failure also affects trading behavior among individuals on capital markets. We use smoking as the most socially accepted example of self-control failure among 13,644 German brokerage clients and compare the trading behavior of 3,553 smokers and 10,091 nonsmokers. Smokers are associated with a higher portfolio turnover unexplained by financial sophistication or wealth effects. Self-control failure also exacerbates overconfidence, social contagion, sensation seeking, and attention grabbing. Overall, self-control failure is costly because it increases the gap between gross and net returns of smokers relative to nonsmokers.
Journal of Empirical Finance , Vol. 63, pp. 73-95, 2021