As on-field success is nowadays the main objective of European soccer clubs, good management needs to extract the highest sport success from the squad talent at hand. Because teams differ in their quality, performance needs to be compared with the best practice of comparable units. One remarkable source of heterogeneity across teams is the squad composition, which can produce gains from diversity together with communication costs. The paper studies the efficiency in sporting performance of soccer teams, paying attention to how the number of foreign players relates to productive inefficiency. Using data for 146 teams in the top 5 European leagues during 10 seasons, we estimate a double heteroskedastic True Random Effects Stochastic Frontier team production function. We find that (i) the number of passes, ball recoveries, and shots from the penalty area improve team efficiency, and (ii) a higher number of foreign players increase inefficiency. Our findings suggest that gains from squad diversity might be offset by communication costs.

中文翻译：

---

外籍球员、球队表现和技术效率：来自欧洲足球的证据

由于球场上的成功如今是欧洲足球俱乐部的主要目标，因此良好的管理需要从现有的球队人才中获取最高的体育成功。由于团队的质量不同，因此需要将绩效与可比单位的最佳实践进行比较。球队之间异质性的一个显着来源是球队的组成，它可以从多样性和沟通成本中产生收益。本文研究了足球队运动表现的效率，关注外籍球员数量与生产效率低下的关系。使用欧洲前 5 个联赛的 146 支球队在 10 个赛季中的数据，我们估计了双异方差真实随机效应随机前沿球队生产函数。我们发现（i）传球、接球和禁区射门的次数提高了球队的效率，（ii）更多的外援会增加效率低下的情况。我们的研究结果表明，球队多样性带来的收益可能会被沟通成本所抵消。