Social equity and the probability of success of biodiversity conservation

•Social equity, economic efficiency and environmental effectiveness are often sought.•Social equity can be necessary for success, but can compromise other goals.•We enhance our understanding of the social equity-conservation success relationship.•The best conservation outcome is often achieved without perfect social equity. Conservation actions generally benefit some groups more than others, and this inequity is thought to affect the probability of achieving conservation objectives. This has led to the common assumption that triple bottom line solutions – those that are effective, efficient, and equitable – are best and most likely to achieve each individual objective. Although this may be true, it has been little tested, and importantly lacks a conceptual foundation for understanding, predicting and evaluating how equity affects conservation outcomes. We describe types of equity relevant to conservation and explore how they may affect the probability of successfully achieving conservation outcomes. Depending on the equity type and context, the relationship between equity and conservation success varies. We find that the best conservation outcome is often achieved without perfect equity; highlighting the risk of ignoring the relationship between equity and success. We offer a conceptual foundation for better addressing this important issue in future research and application.