The influence of social pressure and nationality on individual decisions: evidence from the behaviour of referees

This study considers the influences on agents' decisions in an international context. Using data from five seasons of European cup football matches it is found that referees favour home teams when awarding yellow and red cards. Previous research on referee decisions in national leagues has identified social pressure as a key reason for favouritism. While social pressure is also found to be an important influence in this study, the international setting shows that nationality is another important influence on the decision making of referees. In considering principal-agent relationships account needs to be taken not only of how agents (referees) decide under social pressure but also of how national identity shapes agents' decision making.