Abstract
Voluntary sustainability standards (VSS) can promote environmental and socioeconomic benefits, yet critics contend that they can also create trade barriers. While prior research reports have been mixed with regard to VSS effects, our study examines whether domestic political dynamics and public–private interactions significantly explain some of these outcomes. We investigate Bonsucro certification for Brazilian sugar and ethanol exports to the EU. Bonsucro verifies that exports meet EU biofuels regulations and additional EU criteria. Should influential European interests drive these criteria to be overly stringent, Brazilian exports could suffer. Through qualitative analysis, we show that import-competing interests do not solely account for EU meta-regulation of VSS. Our staggered difference-in-differences analysis reveals that Bonsucro certification correlates with increased EU exports, although its benefits are concentrated mainly among the largest exporters, contributing to export concentration. These findings have broad implications for debates on hybrid governance and the legitimacy of VSS as environmental policy instruments.