The empirical evidence on the economic impacts of diversity is mixed. Many studies in the literature present context dependent and data driven results which are challenging to reconcile with each other. This paper offers a systematic synthesis of the empirical findings on the economic impacts of diversity on innovation, productivity, and the labour market. It presents a structured framework which takes the spatial scale of the analysis in the papers as a reference to understand the inconsistency of some previous predictions and the varying magnitudes of the diversity impact. The empirical findings reconcile more meaningfully when diversity effects are documented discretely at the regional, firm and individual levels. The paper further sets out an agenda for future research and links the findings for policy relevance.