We examine how entrepreneurship and institutional and policy reforms affect development (proxied by the rate of growth in per–capita income). We do so by performing Arellano-Bond GMM estimations on annual data for a large group of developing and developed countries, and covering the period 1990-2002. We focus in particular on the interplay of trade and institutional reforms and entrepreneurship. The empirical results indicate that the interplay of entrepreneurship and institutions, and the interplay of entrepreneurship and policy reforms, influence the growth effects of entrepreneurship. However, the effects are strikingly different. The impact of institutional reform is positive when the level of entrepreneurship is low and negative when it is high. On the other hand, the effect of policy reform is negative when entrepreneurial activity is weak and positive when it is strong. These results are robust to the inclusion of other control variables.