Effect of voluntary sustainability standards in the rice sector under the EU-Vietnam Free Trade Agreement: evidence from the Mekong Delta

Voluntary sustainability standards (VSSs) have become key instruments for promoting sustainability and competitiveness among farmers, within global value chains and EU trade agreements. Under the EU-Vietnam Free Trade Agreement (EVFTA), this study examines sustainability challenges for rice producers in the Mekong Delta (MKD) and how VSSs, rice area, and cooperative membership influence revenues. Using a mixed-methods approach combining 12 stakeholder interviews and a survey of 110 farmers, the study finds that VSS adoption alone is associated with a 28% revenue increase, but this standalone effect is not statistically significant. Certified farmers who are also cooperative members earn 8.7% more than those who are neither certified nor cooperative members, whereas cooperative membership alone is linked to a 62.4% decrease in economic return. Rice area emerges as the strongest predictor of revenue. Despite government efforts to promote environmental programmes, adoption of sustainable and water-saving practices remains limited in the MKD. Broader constraints, such as weak incentives and limited access to extension services, continue to hinder VSS uptake in the rice sector. The findings suggest the need for policies that support climate adaptation, strengthen cooperative governance, and enhance institutional coordination to scale up VSS implementation and ensure more equitable outcomes under the EVFTA.