Network Competition and Team Chemistry in the NBA
研究了一个异质性社交互动模型，其中球员在队内和对手间都有互动，发现NBA比赛中存在正向的队内同伴效应（团队化学）和正负向的对手竞争效应（团队竞争），对理解团队运动中的互动机制有帮助。
Abstract–We consider a heterogeneous social interaction model where agents interact with peers within their own network but also interact with agents across other (non-peer) networks. To address potential endogeneity in the networks, we assume that each network has a central planner who makes strategic network decisions based on observable and unobservable characteristics of the peers in her charge. The model forms a simultaneous equation system that can be estimated by quasi-maximum likelihood. We apply a restricted version of our model to data on National Basketball Association games, where agents are players, networks are individual teams organized by coaches, and competition is head-to-head. That is, at any time a player only interacts with two networks: their team and the opposing team. We find significant positive within-team peer-effects and both negative and positive opposing-team competitor-effects in NBA games. The former are interpretable as “team chemistries” which enhance the individual performances of players on the same team. The latter are interpretable as “team rivalries, ” which can either enhance or diminish the individual performance of opposing players.