Allocative efficiency criteria are satisfied by the competitive model. Because P = MC, in each market in the economy there is no over- or under- allocation of resources in this economy. This is due to the cost of production for the last unit of production is what shows supply, and that cost of production includes only the engineering costs. Though, this result is obtained only if all industries in that economic system are purely competitive. This is the contribution of the models of distribution formed by economists working in the marginalists traditions. The problem is that this is economic theory that is not essentially supported by empirical evidence.