This paper investigates the conjecture that oligopolistic pricing behavior will invalidate the Lucas-Sargent policy-ineffectiveness proposition even if expectations are formed rationally. The procedure is to examine the properties of an analytical macroeconomic model that incorporates a simplified version of the MPS wage-price sector. It is shown that the validity of the conjecture depends upon the precise manner in which lags are built into the price adjustment equation. A crucial condition is isolated and used to motivate an empirical test. The results, based on quarterly U.S. data, are predominantly consistent with the ineffectiveness proposition.

This paper investigates the conjecture that oligopolistic pricing behavior will invalidate the Lucas-Sargent policy-ineffectiveness proposition even if expectations are formed rationally. The procedure is to examine the properties of an analytical macroeconomic model that incorporates a simplified version of the MPS wage-price sector. It is shown that the validity of the conjecture depends upon the precise manner in which lags are built into the price adjustment equation. A crucial condition is isolated and used to motivate an empirical test. The results, based on quarterly U.S. data, are predominantly consistent with the ineffectiveness proposition.