I present a theory of development in which heterogeneously talented entrepreneurs require credit to start new projects and open new sectors. During development the variety of sectors expands, which allows better sorting of entrepreneurial talent. The paper shows that, in addition to increasing the average productivity of matches between agents and sectors, this process also mitigates informational frictions in the …nancial markets. Furthermore, the impact of sectoral variety on the operation of …nancial markets gives rise to an interesting feedback between …nancial development and R&D e¤ort, which may lead to di¤erent types of dynamics. A successful economy exhibits a progressive increase in the variety of sectors, which in turn enhances the operation of …nancial markets. However, a poverty trap may also arise. This situation is characterised by a rudimentary productive structure with poor matching of skills to activities and severely ine¢ cient credit to talented entrepreneurs.