The economic value of local social networks
采用准实验方法，结合双重差分和倾向得分匹配，发现与本地社交网络中关系广泛的“交易撮合者”建立联系的企业，在就业和销售额上获得显著增长。
The idea that local social capital yields economic benefits is fundamental to theories of agglomeration, and central to claims about the virtues of cities. However, this relationship has not been evaluated using methods that permit confident statements about causality. This article examines what happens to firms that become affiliated with ‘dealmakers’—individuals who are unusually well connected in local social networks. We adopt a quasi-experimental approach, which examines firms that added exactly one new individual to their firm, combining difference-in-differences and propensity score matching to address selection and\\ identification challenges. The results indicate that when compared to a control group, firms which link to a dealmaker are rewarded with substantial gains in employment and sales.