Score contribution per author:
α: calibrated so average coauthorship-adjusted count equals average raw count
This paper shows that the ancestry composition shaped by century-long immigration to the US can explain the current structure of global supply chains. Using an instrumental variable strategy combined with a novel dataset that links firm-to-firm global supply chains with their location information and historical migration data, we find that the co-ethnic networks have a positive causal impact on global supply chain relationships between foreign countries and US counties. The positive impact not only exists in supplier–customer relationships but also extends to strategic partnerships and trade in services. The positive impact is stronger in counties in which a larger number of firms are credit constrained, and such a stronger effect becomes even more pronounced when foreign firms are located in countries with weak contract enforcement. The results suggest that co-ethnic networks serve as social collateral to overcome credit constraints and facilitate global supply chain formation.