Local Network Effects in the Adoption of a Digital Platform*
研究了数字平台上的网络效应是否局限于本地，发现一个县现有用户规模显著影响该县新用户数量，而邻近县用户规模则无影响，且网络效应因收入水平而异。
Abstract We examine the extent to which network effects on a digital platform are geographically local. Focusing on the fantasy sports market, we find that the size of a county's existing user base on the platform significantly impacts the number of new adopters in that county, while the size of the user base in nearby counties does not. We also find evidence that network effects are heterogenous across income levels. Guided by these results, we demonstrate that the initial distribution of users across counties can significantly influence the growth of the network over time, and draw implications for optimal seeding strategies.