Summary
Voluntary sustainability standards (VSS) in the coffee sector differ fundamentally in their governance structures, with third-party certifications governed by independent multi-stakeholder organizations and in-house certifications designed and managed by corporations themselves. Whether these governance differences translate into different sustainability outcomes for smallholder farmers remains an open empirical question. This study examines whether third-party and in-house coffee certifications are associated with different economic and ecological outcomes for smallholder farmers in Rwanda. We draw on survey data from 842 coffee farm households and direct ecological field measurements from a subsample of 99 plots. Endogenous switching regression models are used to estimate associations with economic outcomes, and generalized linear mixed models for ecological outcomes. Both certification types are associated with higher yields and gross revenues, but only third-party certifications are associated with higher net coffee income and greater shade tree species diversity. In-house certifications are associated with significantly lower arthropod predation rates. These findings suggest that third-party certifications exhibit a synergy pattern, with concurrent economic and ecological gains, while in-house certifications exhibit a trade-off pattern, where productivity gains are accompanied by negative functional biodiversity associations.