Forthcoming in the American Economic Review <p>The LeChatelier principle, in the form introduced into economics by 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...</p>

We identify two sufficient conditions for games with strategic complementarities to have a unique equilibrium that is "strongly coalition-proof," that is, immune to incentive-compatible deviations by coalitions. If a Nash equilibrium is unique, then it is strongly coalition-proof. Also, if each...