The effect of crowd support: home advantage in football is reduced during the Coronavirus disease (COVID-19) pandemic

As support from other people can influence human behaviour, one may ask how the absence of crowd attendance influences the performance of football (i.e., soccer) players. I address this question by contrasting matches of the Brazilian Championship (1st and 2nd Divisions) in 2019 and 2020, years in which crowd attendance was prohibited in order to fight the Coronavirus disease (COVID-19) pandemic. In the 1st Division, home advantage decreased from 2019 to 2020, as teams that used to play for larger crowds had lower performance at home in 2020. However, no decrease in home advantage occurred in the 2nd Division in the same period. One explanation for this difference is that the beneficial effects of crowd support are more effective in the 1st Division, where players are used to receiving support from larger crowds. Therefore, while fan support can influence the behaviour/performance of players, this may not always happen.