"This paper compares the P-bar model of price adjustment with the currently dominant Calvo specification. Theoretically, the P-bar model is more attractive as it depends upon adjustment costs for physical quantities rather than nominal prices, while incorporating a one-period information lag....

"In a very broad class of dynamic linear models, if agents possess knowledge of current endogenous variables in a least-squares learning process, determinacy of a rational expectations (RE) equilibrium is sufficient but not necessary for learnability of that equilibrium. Thus, since learnability...