The supplementary table (Table S1) presents the estimated parameters of the gravity equation using a Poisson model for the study on "Pulling back the curtain on 'behind the border' trade costs: The case of EU-US agri-food trade." The table includes results for year and country-specific fixed effects, which are not reported for space-saving reasons. The significance levels of the coefficients are indicated by *, , and * for 1%, 5%, and 10% levels of significance, respectively. Sector codes and variable abbreviations are referenced in Table 1 and Table 2, respectively. The square correlation between actual and fitted values is used as a fit measure in count models due to the lack of a comparable $R^2$ in linear models, as noted by Cameron & Trivedi (2010).The supplementary table (Table S1) presents the estimated parameters of the gravity equation using a Poisson model for the study on "Pulling back the curtain on 'behind the border' trade costs: The case of EU-US agri-food trade." The table includes results for year and country-specific fixed effects, which are not reported for space-saving reasons. The significance levels of the coefficients are indicated by *, , and * for 1%, 5%, and 10% levels of significance, respectively. Sector codes and variable abbreviations are referenced in Table 1 and Table 2, respectively. The square correlation between actual and fitted values is used as a fit measure in count models due to the lack of a comparable $R^2$ in linear models, as noted by Cameron & Trivedi (2010).