Assessing the Impact of Seafood Import Monitoring Program (SIMP) on the U.S. Seafood Imports

We examine the trade effects of the Seafood Import Monitoring Program (SIMP), the U.S. traceability initiative targeting illegal, unreported, and unregulated (IUU) fishing. Leveraging SIMP’s phased rollout across seafood products, we employ a gravity model with a staggered Difference-in-Differences framework estimated via Poisson Pseudo-Maximum Likelihood (PPML) using U.S. import data from 2015 to 2023. Our results show that SIMP reduced seafood import value and quantity while raising unit prices, with effects intensifying over time. These trade effects were stronger among exporters facing greater U.S. market power, while the impact by IUU risk level was more nuanced, showing sharper declines among high-IUU countries in subgroup analyses. We also find that SIMP reduced the number of active country-product trade relationships through adjustments at the extensive margin and led to price declines in related but unregulated substitute products, suggesting indirect spillover effects. Our findings provide the first causal evidence on SIMP’s trade impact and underscore the heterogeneous influence of regulatory enforcement depending on exporter compliance capacity and U.S. market leverage.