This paper considers the validity of the Lucas-Sargent Proposition, which concerns the ineffectiveness of countercyclical monetary policy when expectations are rational, under the assumption that prices are "sticky." The model of Sargent and Wallace is modified so as to incorporate stickiness as follows: in each period the price adjusts to the market-clearing value only if the latter is far from the expected value (i.e., when the cost of maintaining an inappropriate price exceeds the lump-sum cost of a revision). Otherwise the price equals the value previously expected. Given this modification, the proposition remains valid.

This paper considers the validity of the Lucas-Sargent Proposition, which concerns the ineffectiveness of countercyclical monetary policy when expectations are rational, under the assumption that prices are "sticky." The model of Sargent and Wallace is modified so as to incorporate stickiness as follows: in each period the price adjusts to the market-clearing value only if the latter is far from the expected value (i.e., when the cost of maintaining an inappropriate price exceeds the lump-sum cost of a revision). Otherwise the price equals the value previously expected. Given this modification, the proposition remains valid.