Stratégies de politique commerciale pour une sortie de la trappe de sous-développement

Relying on a model of new economic geography, this paper focuses on the relationship between trade policy and the economic conditions of take-off. We confirm notably in a trisectoral analysis that both unilateral trade liberalization and import substitution, while influencing the balance between centrifugal and centripetal forces, may be successful in getting the less developed country out of the poverty trap. In our model, technological externalities resulting from sectoral learning spillovers complete the usual presence in such theoretical framework of pecuniary externalities. By this way, we show that the degree of technological diffusion is a determining parameter for a Southern economy. We show also that sectoral trade policies, in the same way as an active industrial policy, favour structural change in the less developed country. Classification JEL : F12, F13, O14