Biodiversity change and increasing within-country economic inequalities represent two of the greatest global challenges of the Anthropocene. The most marginalized in society are often the most vulnerable to biodiversity change but there is no consensus on the relationships between biodiversity change and rising economic inequalities. To address this gap, we conducted a systematic scoping review of the literature and found 27 studies that explicitly examined the relationships between economic inequality and biodiversity. These were predominantly quantitative but also included qualitative, scenario, and review papers. The majority of studies (21/27) found evidence to suggest that more unequal regions had lower levels of biodiversity, and also that wealthier areas had higher levels of biodiversity. However, few studies investigated the causal mechanisms underlying the reported relationships, and there was little consistency in the metrics used to measure either inequality or biodiversity. Future research needs to focus on testing, or in-depth explorations, of causal mechanisms, with both quantitative and qualitative approaches needed. It is crucial that we understand how economic inequality and biodiversity interact if we are to meet the aims of reducing economic inequality and preventing further biodiversity loss
