Policy makers find it difficult to promote economic development through entrepreneurship and SMEs. In this paper we argue that this is because the positive impact of entrepreneurship is overestimated and its negative impact underestimated. It is moreover also because there is no unified scientific approach towards the role of entrepreneurship in economic development. The scholarly fields that have been interested in this, entrepreneurship economics and development economics, have been elaborated in isolation and only recently started to intersect. This growing intersection is however fragmented, ad hoc, not based on a unifying theoretical approach and suffering from lack of proper measurement. Better policy making will hence benefit from the extension and deepening of the intersection of these fields. We contribute in this regard by providing a conceptual basis for the eventual elaboration of such a unified theoretical approach. We do so by providing an up-to-date review of the intersection of the two scholarly fields, by noting the progress and gaps, by delineating the externalities associated with entrepreneurship in development, and by proposing a new synthesis definition of entrepreneurship.