Getting Closer or Drifting Apart?
研究通信成本下降如何影响个体间与群体间的分离程度，发现个体分离减少而群体分离增加，并利用1990年代互联网兴起前后经济学家的合著数据检验模型。
Advances in communication and transportation technologies have the potential to bring people closer together and create a "global village." However, they also allow heterogeneous agents to segregate along special interests, which gives rise to communities fragmented by type rather than by geography. We show that lower communication costs should always decrease separation between individual agents even as group-based separation increases. Each measure of separation is pertinent for distinct types of social interaction. A group-based measure captures the diversity of group preferences that can have an impact on the provision of public goods. While an individual measure correlates with the speed of information transmission through the social network that affects, for example, learning about job opportunities and new technologies. We test the model by looking at coauthoring between academic economists before and during the rise of the Internet in the 1990s.