Ports’ criticality in international trade and global supply-chains

Abstract Ports form the backbone of the global economy. By combining a vast database of ship tracking data with bilateral trade data and input-output tables, we highlight the critical role of specific ports in global supply chains and economies. For some countries, we find that 43.5% of economic activity is dependent on trade going through a single port. The top ten global ports influence 9.3% of the global economy, of which the port of Shanghai alone embeds 1.7% of global output. Ports are even more critical in some sectors, such as the mining and quarrying sector, for which 82% of trade is transported by maritime transport. We estimate how changes in final demand will be routed through ports, revealing that for every US$1000 increase in final demand a country’s ports experience a US$18.3 increase in imports on average, and up to US$108 increase in low income countries and small islands.