We use a one-factor two-sector model of comparative advantage with uncertainty to com- pare the effects of different specialization levels on growth under various scenarios. We derive the static and dynamic optimal level of specialization under the centralized and the decen- tralized economy. We identify the conditions under which the socially optimal specialization level entails positive investment in the comparatively disadvantaged sector. We show that in this case the socially optimal solution cannot be reached by the decentralized economy which is in fact characterized by over-specialization. We conclude presenting a simple tax-based re- distributive mechanism able to achieve the optimal level of specialization in a decentralized economic system.