A Friend Like Me: Modeling Network Formation in a Location-Based Social Network
研究了基于位置的社交网络中用户如何建立社交链接，利用传记、地理、移动和短信四个维度的相似性度量，发现同质性显著影响网络形成，并通过天气冲击作为工具变量解决内生性问题。
This article studies the strategic network formation in a location-based social network. We build an empirical model of social link creation that incorporates individual characteristics and pairwise user similarities. Specifically, we define four user proximity measures from biography, geography, mobility, and short messages. To construct proximity from unstructured text information, we build topic models using Latent Dirichlet Allocation. Using Gowalla data with 385,306 users, 3 million locations, and 35 million check-in records, we empirically estimate the model to find evidence on the homophily effect on network formation. To cope with possible endogeneity issues, we use exogenous weather shocks as our instrumental variables and find the empirical results are robust: network formation decisions are significantly affected by our proximity measures.