We show that professional soccer players and their coaches exhibit reference-dependent behavior during matches. Controlling for the state of the match and for unobserved heterogeneity, we show on a minute-by-minute basis that players breach the rules of the game, measured by the referee’s...

We study how students’ social networks emerge by documenting systematic patterns in the process of friendship formation of incoming students; these students all start out in a new environment and thus jointly create a new social network. As a specific novelty, we consider cooperativeness, time...