On the efficient-market view expressed by Scholes, however, the demand curve for a corporation's stock is flat: "... the demand curve facing individual shareholders is essentially horizontal" (Scholes 1972, p. 182). Equivalently, the price elasticity of demand "the percentage change in the quantity of a good demanded divided by the corresponding percentage change in its price" (Begg, Fischer, and Dornbusch 1997, p. 57) is in the case of stock "virtually infinite" (Scholes 1970, p. 1). Above a certain price level, the stock would not be purchased at all; below that level, there would be effectively infinite demand for it. The view that the demand curve for a stock is flat seems to have been deeply counterintuitive to traditional finance scholars, and I suspect remains so to many practitioners, yet Scholes concluded that his Ph.D. research, an empirical study of "secondary distributions" (sales of large blocks of already-issued stock), was consistent with this view (Scholes 1970, 1972).

Donald MacKenzie, An Engine, Not a Camera, loc. 1503