Written by Keith Ingersoll, Edmund Malesky and Sebastian M. Saiegh, and published in the Journal of Sports Analytics, “Heterogeneity and team performance: Evaluating the effect of cultural diversity in the world’s top soccer league” is an academic study focused specifically on determining the impact cultural diversity has on the success of European soccer (football) clubs. Using data science, the authors determine that those clubs which are more culturally diverse have a greater rate of success on the pitch.
I had heard it said by a commentator during a FIFA World Cup broadcast in 2014 that the national teams whose squads were comprised of players who played their “club football” in Europe had an advantage. It wasn’t only because the European leagues are considered the most competitive in the world. The announcer believed it was also because of the exposure those players had to the different styles of play utilized by clubs across the continent.
This seemed plausible to me, but was there any actual evidence to back up such claim? Could exposure to such diversity translate to better performances? It was with these questions in mind that I sought out such a study. “Heterogeneity and team performance” goes a long way towards answering them both.
The UEFA (Union of European Football Associations) Champions League is an annual competition comprised of the top clubs from around the continent. It is by far the most popular club competition in the world, with viewership numbers in the millions. In order to qualify for the Champions League, a club must have finished in the top four or five positions of their domestic league the previous season. In “Heterogeneity and team performance”, Ingersoll, Malesky and Saiegh focus on the English, French, German, Italian and Spanish clubs who competed in the Champions League during a ten year stretch from 2003-2012.
Ingersoll, Malesky and Saiegh collected data on 168 players across 41 clubs. Each of the clubs were given a cultural diversity rating based on a calculation referred to by the authors as “linguistic distance”. This, they explain, is to account for clubs comprised of players who may be from different countries, but where the same language is spoken. (For example, South American players who play for Spanish clubs.)
Keeping in mind to address potential impacts to the results of the study, such as the financial resources of each club, player movement, etc., Ingersoll, Malesky and Saiegh used the linguistic distance measurement, and per-goal difference as variables. They then used total and average roster value as a control variable. To measure overall club quality, they cited such resources as player rankings published by ESPN and The Guardian as a means to establish player quality and averaged that across each club. It seems that the numbers do in fact back up the assertion made by that commentator back in 2014. More diverse teams do have a greater rate of success.
Put simply, goal differential is the number of goals a club scores minus the number of goals allowed. It’s an especially effective measurement for success, because the higher the goal differential, the more likely a club is winning or drawing matches, as opposed to losing them. As you can see in the above chart taken directly from the study, clubs with a greater rate of linguistic diversity also had higher average goal differential per season.
If cultural diversity translates to success in soccer, does it not also stand to reason that the same would be true across a myriad of endeavors? The cultural influence of soccer, the UEFA Champions League, and of clubs such as Barcelona, Real Madrid, Juventus, Bayern Munich, Paris San Germain, Manchester United and Arsenal cannot be overstated. Soccer is a game played and watched by billions around the planet. The most successful clubs in the most successful competition are comprised of the most talented players from around the world. To see a collection of players from diverse backgrounds work together towards a common goal and be rewarded for it, should serve as an inspiration for soccer fans around the world. Maybe, just maybe, soccer fans will see that success, and attempt to emulate that in their own lives.