The 12th man?: refereeing bias in English and
German soccer

Buraimo, B; Forrest, DK; Simmons, R

Abstract

The paper investigates potential bias in awards of player disciplinary sanctions, in
the form of cautions (yellow cards) and dismissals (red cards) by referees in the English Premier
League and the German Bundesliga. Previous studies of behaviour of soccer referees have not
adequately incorporated within-game information.Descriptive statistics from our samples clearly
show that home teams receive fewer yellow and red cards than away teams. These differences
may be wrongly interpreted as evidence of bias where the modeller has failed to include withingame
events such as goals scored and recent cards issued.What appears as referee favouritism
may actually be excessive and illegal aggressive behaviour by players in teams that are behind
in score. We deal with these issues by using a minute-by-minute bivariate probit analysis of
yellow and red cards issued in games over six seasons in the two leagues. The significance of
a variable to denote the difference in score at the time of sanction suggests that foul play that
is induced by a losing position is an important influence on the award of yellow and red cards.
Controlling for various pre-game and within-game variables, we find evidence that is indicative of
home team favouritism induced by crowd pressure: in Germany home teams with running tracks
in their stadia attract more yellow and red cards than teams playing in stadia with less distance
between the crowd and the pitch. Separating the competing teams in matches by favourite and
underdog status, as perceived by the betting market, yields further evidence, this time for both
leagues, that the source of home teams receiving fewer cards is not just that they are disproportionately
often the favoured team and disproportionately ahead in score.Thus there is evidence
that is consistent with pure referee bias in relative treatments of home and away teams.

Citation

German soccer. Journal of the Royal Statistical Society: Series A, 173(2), 431-449. https://doi.org/10.1111/j.1467-985X.2009.00604.x

• Journal Article Type: Article
• Publication Date: Jan 1, 2010
• Deposit Date: Dec 12, 2011
• Journal: Journal of the Royal Statistical Society, Series A (Statistics in Society)
• Print ISSN: 0964-1998
• Publisher: Wiley
• Peer Reviewed: Peer Reviewed
• Volume: 173
• Issue: 2
• Pages: 431-449
• DOI: https://doi.org/10.1111/j.1467-985X.2009.00604.x
• Publisher URL: http://dx.doi.org/10.1111/j.1467-985X.2009.00604.x