This paper investigates the determinants of strongly enforceable social and environmental provisions in Preferential Trade Agreements (PTAs). While a growing literature has examined the effects of sustainability provisions on trade outcomes and policy implementation, less attention has been paid to the factors shaping their adoption, particularly when focusing on provisions supported by binding legal commitments. This paper shows that political proximity between partner countries plays a central role in the inclusion of high-enforcement sustainability provisions. Countries with more similar political and institutional characteristics are significantly more likely to embed binding social or environmental commitments in their trade agreements. By contrast, differences in economic structures, trade patterns or environmental characteristics appear less systematically associated with the adoption of such provisions. These results suggest that while sustainability clauses have become widespread in modern PTAs, the adoption of strongly enforceable commitments depends importantly on political and institutional compatibility between negotiating partners. The analysis relies on a newly constructed dataset of social and environmental provisions in PTAs that identifies provisions formulated in legally binding terms based on the legal language of agreements.

In September 2015, the U.S. Environmental Protection Agency revealed that Volkswagen had installed defeat devices to manipulate emissions tests, triggering the Dieselgate scandal. This paper examines how this reputational shock affected international trade in diesel-powered passenger cars, focusing on intra-European exports. Using product-level bilateral trade data and a difference-in-differences strategy estimated with a Poisson pseudo-maximum likelihood (PPML) estimator, we find that the Dieselgate led to a significant decline in diesel car exports within the European Union. This average effect masks substantial heterogeneity across producers. The contraction is primarily driven by German-branded vehicles, which were directly associated with the scandal, while other exporters experienced more limited or offsetting changes, consistent with substitution across producers. We further show that media exposure and social media sentiment help explain cross-country differences in responses, particularly for German diesel cars. Overall, our findings indicate that reputational shocks can affect international trade both through aggregate demand effects and through reallocations across producers.

Maritime transport is a cornerstone of globalization but also a major source of localized air pollution in port cities. While the contribution of shipping emissions has been widely studied through inventories and case studies, causal evidence on their impact on ambient air concentration remains scarce. This paper exploits the Red Sea crisis of December 2023, a large and unexpected geopolitical shock that sharply reduced vessel arrivals in European ports, to identify the causal effect of maritime traffic on urban pollution. We assemble a novel daily panel dataset covering 613 ports, combining ship-level Automatic Identification System (AIS) records with high-frequency pollution and meteorological data. Our estimates show that shipping substantially increases nitrogen oxides in European ports: a 1,000 DWT rise in hourly traffic raises daily average NO2 concentrations by 0.017 µg/m3, with effects detectable up to 4 km. Counterfactual estimates suggest shipping accounts for about 4% of ambient NO2 on average, implying substantial localized health costs. No robust causal effects are found for SO2 or particulate matter, underscoring that NOx emissions appear as the primary local externality of maritime transport. Finally, comparing city- and port-level analyses highlights the importance of spatial granularity, reflecting a trade-off between spatial dilution and broader urban confounding. While city-level regressions capture the overall pollution environment of port cities, the port-level approach uncovers more spatially concentrated effects that are more tightly linked to maritime activity.