@TechReport{iza:izadps:dp13578,
            	author={Bryson, Alex and Dolton, Peter and Reade, J. James and Schreyer, Dominik and Singleton, Carl},
            	title={Experimental Effects of an Absent Crowd on Performances and Refereeing Decisions during COVID-19},
            	year={2020},
	month={Aug},
            	institution={Institute of Labor Economics (IZA)},
            	address={Bonn},
            	type={IZA Discussion Paper},
            	number={13578},
            	url={https://www.iza.org/index.php/publications/dp13578},
	abstract={The Covid-19 pandemic has induced worldwide natural experiments on the effects of crowds. We exploit one of these experiments currently taking place over several countries in almost identical settings: professional football matches played behind closed doors. 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 refereeing decisions.},
	keywords={referee bias;natural experiments;home advantage;COVID-19;Coronavirus;attendance;social pressure},
            }