Summary
This systematic review examines how participation in Voluntary Sustainability Standards (VSS) affects smallholder farmers’ yields, prices, input costs, crop income, and household income in low- and middle-income countries, synthesising evidence published between 2008 and 2024 and exploring the conditions under which VSS improve economic outcomes.
Using a systematic review methodology, the authors screened more than 30,000 records from Web of Science and CAB Abstracts and included only rigorous counterfactual studies comparing certified and non-certified farmers. The final evidence base comprised 62 studies (49 from 2008-2018 and 13 from 2019-2024), covering 21 countries, multiple agricultural commodities, and seven major VSS, with coffee and Fairtrade receiving the greatest research attention.
The review finds that VSS participation is most consistently associated with higher crop income, with more mixed evidence for improvements in yields and prices, little evidence of reduced input costs, and limited evidence that gains translate into higher household income. A notable insight is the persistent disconnect between farm-level improvements and broader household wellbeing, with outcomes varying substantially by crop, country, cooperative effectiveness, access to credit, and local infrastructure.
The report recommends strengthening farmer cooperatives and other support structures, integrating household-level and resilience indicators into VSS design and monitoring, complementing price premiums with broader livelihood support, and investing in enabling infrastructure and market systems. It also calls for expanding the evidence base beyond the relatively small and declining body of rigorous studies currently available, particularly through more holistic, context-sensitive, and longitudinal research on smallholder livelihoods.
The supplementary data sheet can be found here.
The 2019 Evidensia systematic review, which this report builds on, can be found here.
An exploration of the insights that can be gained from studies without a counterfactual can be found here.