The impact of skilled immigrants on their local teammates’ performance

ABSTRACT

We use the Bosman ruling, which invalidated restrictions on the maximum number of foreign players allowed on professional football teams, to identify a causal positive impact of foreign players in German Bundesliga clubs on the individual performance of their domestic teammates.

KEYWORDS:

• Immigration
• peer effects
• labour market regulation
• labour mobility

JEL CLASSIFICATIONS:

• J08
• J11
• J28
• J6
• M54

Disclosure statement

No potential conflict of interest was reported by the authors.

Notes

¹ Other studies that also use soccer data for their empirical analyses include, for instance, Szymanski (2000), Apesteguia and Palacios-Huerta (2010) and Miklós-Thal and Ullrich (2016).

² We cross-checked the information we use for a random sample of players on various websites and found the data we use to be identical across these websites.

³ Results are robust but lose their statistical significance if players with fewer than five games per season are included. Forty players participated in less than 10 games per season.

⁴ See EuGH, D.f. 15.12.1995, C-415/93.

⁵ Averaging over the season helps to reduce noise and subjective influence of individual experts’ performance ratings. The same performance measure has been used in other studies, for example, Miklós-Thal and Ullrich (2016).

⁶ The performance index consists of variables that significantly influence the final score of a match, including number of goals; assists; pass success rate; cross success rate; dribbling success rate; shots on target; red cards; yellow cards; clearances, blocks and interceptions; and the saves-to-shots ratio by the goalkeeper (Franck and Nüesch 2010). Unfortunately, this measure is not available for the period of our study.