Assessing the Day Delay Effect of Port Congestion on US Agricultural Exports

Relative to the rest of the world, shipping delays have been a problem in the US even prior to COVID‐19 but became more publicized and exacerbated during the pandemic. While previous studies have focused on COVID‐19 shocks using event study methods, we quantify the effect of congestion, measured as the average number of days a vessel spends in port, on US agricultural container exports using monthly export data from US ports. We estimate, in general, that a one‐day increase in congestion reduces containerized US agricultural exports by 2.5% in quantity and 1.1% in value. This quantity effect is comparable to an ad‐valorem tariff of roughly 12%–17% points. Container congestion reduces monthly exports of agricultural products by 77 thousand metric tons and $43.6 million during the pre‐pandemic period 2016–2019. For 2020–2021, these losses increase to 228 thousand metric tons and $111 million. Western ports, in particular, experience the most pronounced losses across all regions, especially on bulk commodity exports with an average monthly loss of $89.0 million after the pandemic and $26.3 million for the pre‐pandemic level. After the pandemic, the total loss in quantity of Western ports accounts for about 90% of the sum of all US ports, and the loss in value for about 70%.