LeChatelier effects confirm the intuition that constrained decisions are not only suboptimal but also restrained in the sense of being less elastic. Samuelson (1947) introduced this idea into economics and showed that it blends neatly with economic models of decision making under certainty, being particularly well suited to the competitive firm. As emphasized by Silberberg (1971), linearity of the objective function combines with convexity in the constraint, imposed by the production technology, to yield envelope results at the first order, and LeChatelier effects at the second, as powerful consequences of the maximization hypothesis. The envelope results of primary interest in producer theory, Shephard's Lemma for cost functions and Hotelling's Lemma for profit functions, are equality relations reflecting the firstorder stationarity of an optimum. LeChatelier effects, in contrast, are inequality relations reflecting the restrained nature of short-run responses compared with long-run, less constrained responses. Thus, the quantities of labor demanded and output supplied are more elastic with respect to wage rate and output price changes in the long run than in the short run. These LeChatelier predictions pertain to a firm that has fully adjusted to an exogenous set of factor and output prices and thus apply only in the neighborhood of a long-run equilibrium configuration for the firm. However, they apply equally well whether capital and labor are substitute or complementary factors of production. Milgrom and Roberts (1996) have established a global LeChatelier principle under the assumption that capital and labor are always substitutes, or always complements, in production, a stipulation that is necessarily true for the infinitesimal changes contemplated in the local LeChatelier predictions. When the firm makes decisions while facing uncertainty about output price, risk preferences influence behavior if the uncertainty cannot be fully diversified through futures contracts or the sale of ownership shares, as in the case of closely held family businesses, such as some of those