Page "Perfect competition" Paragraph 17

Steve Keen notes, following George Stigler, that if firms do not react strategically to one another, the slope of the demand curve that a firm faces is the same as the slope of the market demand curve.

Hence, if firms are to produce at a level that equates marginal cost and marginal revenue, the model of perfect competition must include at least an infinite number of firms, each producing an output quantity of zero.

As noted above, an influential model of perfect competition in neoclassical economics assumes that the number of buyers and sellers are both of the power of the continuum, that is, an infinity even larger than the number of natural numbers.

K. Vela Velupillai quotes Maury Osborne as noting the inapplicability of such models to actual economies since money and the commodities sold each have a smallest positive unit.