Supply Chain Disruptions: Evidence from the Great East Japan Earthquake

This paper quantifies the spillover effect of exogenous shocks, such as earthquakes, on other firms through the supply chain network. Combining micro data on inter-firm transaction networks and geographic information systems, we examine firms' sales growth and transaction relationships outside the tsunami-hit areas before and after the Great East Japan Earthquake. We find that sales growth shows a negative but insignificant effect for firms with suppliers in the affected areas and a negative and significant effect for firms with customers in the affected areas. When we focus on exiting firms in the affected areas as the firms from where the spillovers originated, the sales growth of linked firms outside the affected areas exhibits negative and significant effects for both upstream and downstream firms. Furthermore, significantly negative effects on downstream firms are shown for not only directly linked firms but also indirectly linked firms, with two and three degrees of separation. Finally, we find that firms tend to establish new transactions when they have transaction partners in the affected areas.