Diversification, Market Entry, and the Global Internet Backbone
研究了买家为管理供应商中断风险而进行的供应商多元化如何影响全球互联网骨干网的需求和供应商进入，发现多元化在2005-2021年间解释了大量进入和剩余创造，且供应商无法完全获取多元化社会效益导致的扭曲与业务窃取扭曲相当。
Abstract In many industries, buyers diversify their supplier base to manage supplier disruption risk. We investigate the importance of such diversification as a determinant of demand and supplier entry in the context of the internet backbone, the worldwide network of undersea fibre-optic cables that underpins the internet. We specify a model of international bandwidth demand and cable operators’ dynamic entry and supply choices. The model is estimated using novel data on cross-border data flows, prices, cable characteristics, and disruptions. Counterfactual analysis reveals that supplier diversification accounts for a large share of entry and surplus created between 2005 and 2021. Relative to the socially optimal level of entry, distortions due to suppliers’ inability to capture fully the social benefits of diversity are as large as distortions due to business stealing.