Cultural Assimilation Through Yellow Cards

Researchers from the Catholic Univeristy of Leuven in Belgium looked at data from the English Premier League — the soccer league with the highest number of international players — to look at differences in the number of penalties collected by players from different regions of Europe. If you believed the stereotype that southern Europeans were picking up the most penalties… well, yeah you’re right:

The positive and statistically significant coefficient for the Southern Europe dummy indicates that southern European players have  more  disciplinary points  than  British  players.  The  negative  and statistically significant coefficient  for the Northern Europe dummy  indicates  that northern European players  incur less football penalties  on  the  field  than  British  players. 

However, that’s not the end of the story. It turns out that Southern European players pick up fewer penalties the longer they stay in the league. Specifically, "one additional year of English Premier League experience reduces the disciplinary points for Southern European players by around 5%, as compared to the reference category of British players."

The authors write that "after paying the consequences of playing according to their home set of norms during their early seasons in the English Premier League, migrant football players adapt their behavior to the local standards." 

I do wonder if there’s any chance referee bias plays a role here. Studies of NBA officiating have shown evidence of racial bias in foul calls. It may very well be true that Spanish, Italian, and Portuguese players are used to a rougher style of play, but could the refs also be more likely to call them out on it — especially when they’re new in the league?