Choking under pressure – Evidence of the causal effect of audience size on performance
利用NBA比赛日天气变化作为观众人数的外生变量，研究发现观众越多，主场球队在比赛初期的罚球表现越差，支持“主场失常”而非“主场优势”理论。
We analyze performance under pressure and estimate the causal effect of audience size on the success of free throws in top-level professional basketball . We use data from the National Basketball Association (NBA) for the seasons 2007/08 through 2015/16. We exploit the exogenous variation in weather conditions on game day to establish a causal link between attendance size and performance. Our results confirm a sizeable and strong negative effect of the number of spectators on performance. Home teams in (non-critical) situations at the beginning of games perform worse when the audience is larger. This result is consistent with the theory of a home choke rather than a home field advantage. Our results have potentially large implications for general questions of workplace design and help to further understand how the social environment affects performance. We demonstrate that positive feedback from a friendly audience does affect performance negatively.