Does port infrastructure investment pay off only at some ports?
Core argument: With 80% of international trade carried by ships, the authors find that port infrastructure investment yields positive returns net of costs at only a minority of US ports, so gains depend on proper targeting.
80% of [international] trade is carried by ships. Ports are susceptible to disruptions, causing costly delays. To explore the drivers of welfare gains from investing in infrastructure, we consider how these gains depend on both the characteristics of the treated port, as well as those of the set of ports it decongests.[The] empirical framework combines insights from queueing theory to capture port technology, with tools from demand estimation and novel datasets, to quantify the costs of disruptions and evaluate transportation infrastructure investment. Our analysis unveils three policy-relevant messages: (i) investing in port infrastructure can lead to substantial trade and welfare gains, but only if targeted properly– in fact, net of costs, investment has positive returns at a minority of US ports; (ii) there are sizable spillovers across ports, as investing in one port can decongest a wider set of ports, suggesting that coordinated decision-making may result in more efficient investment decisions; (iii) [by raising the likelihood that capacity constraints will bind], macroeconomic volatility can drastically change returns to investment and their geography.



