We examine the effect of card (yellow and red) collection on player remuneration under the salary cap in Major League Soccer (MLS). The data contain 1478 observations of 731 players under contract between 2015 and 2019. Though the number of yellow cards a player collected had a significant impact, the number of red cards collected was not found to be a significant factor. On average, when a player has accumulated more than eight yellow cards over the course of the regular season, his salary was dropped substantially. If a player receives more than two red cards, his salary was decreased. A key result was that players who were aggressive without crossing the line to the point of being ejected from the field of play received comparatively higher salaries.

我们研究了在大联盟足球（MLS）薪金上限下收取卡（黄色和红色）对球员薪酬的影响。数据包含2015年至2019年之间根据合同签约的731名玩家的1478​​条观察结果。尽管收集到的黄牌数量有重大影响，但发现收集到的红牌数量并不是一个重要因素。平均而言，当一名球员在常规赛期间累积了超过八张黄牌时，他的薪水就大大降低了。如果玩家收到两个以上的红牌，则其薪水会降低。一个关键的结果是，那些积极进取但没有越过界限直到被踢出比赛场地的球员获得了相对较高的薪水。