The Le Chatelier Principle

The Le Chatelier principle, in the form introduced into economics by Paul A. Samuelson, asserts that, at a point of long-run equilibrium, the derivative of long-run compensated demand with respect to own price is larger in magnitude than the derivative of short-run compensated demand. The authors introduce an extended Le Chatelier principle that applies also to large price changes and to uncompensated demand as well as to a wide range of concave and nonconcave maximization problems outside the scope of demand theory. This extension also clarifies the intuitive basis of the principle.