Conservation and development agendas often are seen as in contradiction and, in the past, most forest policy was driven by only one such agenda. Yet leading conservation policies such as protected areas (PAs) increasingly are understood to vary in how development considerations are integrated, within PA types, given the starting point of conservation. Similarly, development policies such as logging concessions can integrate conservation. Sustainable forest management pushes integration from a starting point of development. One of the most visible initiatives of this type is the certification of logging concessions − such as by the Forest Stewardship Council (FSC) − to reduce various impacts of logging. The cost of sustainable management may lead a firm not to certify any given concession, yet the potential benefits could lead firms to voluntarily certify at least some concessions (including as perhaps firms could benefit from strategies that raise forest loss elsewhere). Our empirical analyses of two countries, Peru and Cameroon, aid in understanding what actually has happened in certified sites for the relatively ‘early days’ of such certifications. We control for unobserved factors’ influences over space and time, without which impact − sometimes perverse − is mistakenly attributed to FSC certification (FSCC). For Peru, we see no average FSCC deforestation impact in our study area (almost all concessions). One region, Madre de Dios, has an average reduction of 0.07% per year. For Cameroon, we find a small average FSCC deforestation impact of 0.02% per year in our study area (all concessions), though in four of five regions there is no statistically significant effect. We suggest that, as available data improve, more impact may be seen in some conditions.