Are the financially and institutionally strongest clubs capable of systematically reaching the top positions in the European national football leagues treated differently in terms of awarded sanctions because of the external off-the-pitch pressure they can put on match officials? This study helps shed some light on this controversial question fiercely debated among fans and sports journalists and extends our knowledge of how football match officials may be un-consciously influenced by external (social) forces. Except for France where the evidence is weak, data analysis of the top five European leagues for the seasons from 2011-2012 to 2017-2018 provides empirical evidence supporting the existence of referees’ off-the-pitch strongest team bias. In fact, in England, referees award significantly more yellow cards and total booking points (an aggregate measure of yellow and red cards) to the opponents’ players, and in Italy, Germany, and Spain, significantly fewer yellow cards and total booking points are given to the top teams’ players. The referees’ strongest team bias comes on top of the referees’ home bias, as discussed in the previous literature, and displays a non- eligible size that can reach approximately the same size of the referees’ home bias in some cases.
JEL codes: A12; C21; C52; Z20.