How Widespread Are Social Network Effects? Evidence from the Early Twentieth-Century United States
提出一种基于页面的方法识别邻近个体，比较同区域与不同区域工人对在同一行业工作的倾向，发现20世纪初美国70大城市中同区域工人更可能在同一行业工作，倾向增加约14%-20%，且对单身女性和同国移民更强。
How widespread are social network effects? To answer this, I introduce a page-based approach for identifying individuals living in close proximity and compare how the propensity to work in the same industry varies among worker pairs residing in the same versus different areas. Across the 70 largest cities in the early twentieth-century United States, those from the same area are more likely to work in the same industry. On average, the increase in propensity is around 14%–20% of the baseline mean. These effects also tend to be stronger among single women and migrants from the same country of origin.