We study the trade effects of the 2021 supply chain disruptions on containerized agricultural exports from California ports. Our event studies show that port congestion and container shortages reduced agricultural exports by 22% from May to November 2021. The export losses exceed $3.2 billion and vary substantially across commodity groups, with California tree nut producers facing the brunt of the financial repercussions. California agriculture's losses surpass those from the 2018 China-US trade war by far. The export disruptions mirror the fact that California ports are among the least efficient globally.

This paper assesses the impact of the 2021/22 maritime shipping disruptions on US tree nut exports and domestic inventories. Using detailed trade data for almonds, pistachios, and walnuts and counterfactual empirical methods that account for treatment dynamics, we estimate the trade response to maritime shipping disruptions at the US port and commodity level. We find that tree nut shipments were 457 million pounds or $943 million below the counterfactual between May 2021 and July 2022. Almonds experienced the brunt of those trade losses, while pistachio and walnut exports recorded smaller losses and recovered faster. Our estimates imply that maritime shipping disruptions are a primary driver of surging tree nut inventories. Without the trade destruction caused by maritime shipping disruptions, the almond inventory could have been 38.7% lower and close to the long‐run average in the 2021/22 marketing year. [EconLit Citations: F14, Q17].