Débouchés, Théorie des
Generally regarded as the main original contribution of J.B. Say to economic science, this theory of outlets or of vent affirms that a general glut or general over-production is impossible. If all products could be had for nothing, men would everywhere spring into existence to consume them. Products are bought with other products. Therefore each product is more in demand as other products increase and bid against it. In other words, as the same product constitutes the producer’s demand and the consumer’s supply, a general excess of supply over the general demand is absurd. Moreover, human desires expand indefinitely. So long as these are unsatisfied there can be no over-production except from lack of purchasing power arising from under-production on the part of the would-be purchasers.