Causal effects of an absent crowd on performances and refereeing decisions during Covid-19

Publication date: 11 Dec 2020 | Publication type: NIESR Discussion Paper | NIESR Author(s): Dolton, P | External Author(s): Bryson, A; Reade, J.J; Schreyer, D; Singleton, C | JEL Classification: C90, D91, L83, Z20 | NIESR Discussion Paper Number: 524


The Covid-19 pandemic has induced worldwide natural experiments on the effects of crowds.  We exploit one of these experiments that took place over several countries in almost identical settings: professional football matches played behind closed doors within the 2019/20 league seasons.  We find large and statistically significant effects on the number of yellow cards issued by referees.  Without a crowd, fewer cards were awarded to the away teams, reducing home advantage.  These results have implications for the influence of social pressure and crowds on the neutrality of decisions.

Keyword tags: 
Attendance; Coronavirus; Covid-19; Home advantage; Natural Experiments; Referee Bias; Social Pressure