Penalty kicks as cross-fertilization: On the economic psychology of sports

We review some topics in which soccer penalty kicks are related to phenomena in game theory, decision making and psychology. In particular, we discuss the game theoretic analysis of the kicker's and goalkeeper's behavior and its relation to the concept of mixed strategy Nash Equilibrium. The main idea is that both players should not follow a predictable strategy, and therefore should choose different strategies over time. We also review the action bias of goalkeepers in penalty kicks, which results in them almost always jumping to one of the sides although staying in the goal's center is in fact a good strategy given the empirical distribution of kicks. We then turn to the order effect in penalty shootouts, and the debate to what extent kicking first gives the team an advantage in the shootout. These topics illustrate the opportunities offered by interdisciplinary research that combines sports with social sciences such as economics and psychology. While this interdisciplinary literature has grown significantly in recent years, research opportunities in this area abound and we hope that this article will encourage the readers to contribute to it.