Crisis sociales y singularidades. Los fundamentos microeconómicos de las crisis sociales.

In this paper we show the strong relation existing between efficiency and social welfare. We introduce the concept of Negishi path, a differentiable manifold that shows the relation between distributions of social weights and efficient allocations. We show that it is possible to assign to each efficient allocation a certain level of social welfare, and that given the total resources of an economy and the utilities of its agents, there exits a maximal level possible of social welfare for this economy. This level will be called the Negishi number and it is independent of the distribution of the total resources. We analyze also, the strong relation existing between social crisis and distribution of the initial resources, with this object we introduce the concept of singular economies, and we show that, for these economies small changes in the endowments imply big and unpredictable social changes in the social structure and in the level of social welfare. Finally we introduce in the framework of the General Equilibrium Theory, a definition of developed and underdeveloped economies. Our guide in this trip will be the Negishi approach.