Since producers act to maximize their utility, each producer will generate as much of the consumers' good as possible without allowing his or her marginal return to drop to zero or below. The calculation we followed for Smith can be thought of as a decision procedure, repeated iteratively by each producer until no additional positive marginal return can be obtained. Thus total production of the consumers' good halts just below the break-even point, and the total stock produced is such that the marginal return approaches zero. Equivalently, the selling price of the incremental unit approaches its total marginal cost of production, including interest. (The producers are here considered purely in their function as investors in the productive process. If a producer also contributes labor to the product, then he or she also realizes earnings from that labor, but these can be considered separately from his or her marginal return as an investor.)
In summary, in a free market (without risk or uncertainty) the price of a consumers' good approaches both its marginal (money) value to consumers (
) and its marginal cost of production. Individual buyers and sellers may know nothing about the connections among these variables. Nevertheless, as they seek to maximize their personal utilities, these relationships arise out of their competitive interaction. The prevailing market price, it should be noted, is not arbitrarily set by any buyer or seller, but is determined by the natural value scales of all the human beings acting in the market. 
