A Keynesian idea of considerable historical importance is that, in the presence of a liquidity trap, a competitive economy may lack--despite price flexibility--automatic market mechanisms that tend to eliminate excess supplies of labor. The standard classical counterargument, which relies upon...

Many macroeconomic models involving rational expect at ions give rise to an infinity of solution paths, even when the models are linear in all variables. Some writers have suggested that this non-uniqueness constitutes a serious weakness for the rational expectations hypothesis. One purpose of...

Given the influence of Milton Friedman ,it is hard to keep from identifying "monetarisms" with the advocacy of a policy rule that would require the money stock to grow at a constant rate and prohibit cyclical adjustments in government spending or in tax schedules. This identification is somewhat...

This paper reconsiders a result obtained by Sargent and Wallace, namely, that price level indeterminacy obtains in their well-known model if the monetary authorities adopt a policy feedback rule for the interest rate rather than the money stock. Since the Federal Reserve seems often to have used...

So-called "spurious regression" relationships between random-walk (or strongly autoregressive) variables are generally accompanied by clear signs of severe autocorrelation in their residuals. A conscientious researcher would therefore not end an investigation with such a result, but would likely...

Consider a rational expectations (RE) model that includes a relationship between variables `x_t` and `z_(t+1)`. To be considered structural and potentially useful as a guide to actual behavior, this model must specify whether `x_t` is influenced by the expectation at t of `z_(t+1)` or,...

Cochrane (2007) has strongly questioned the basic economic logic of current mainstream monetary policy analysis, arguing that the standard notion --that "determinacy" of a rational expectations (RE) equilibrium suffices to imply that stable inflation behavior will be generated -- is incorrect....

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...

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....

It is argued that learnability/E-stability is a necessary condition for a RE solution to be plausible. A class of linear models considered by Evans and Honkapohja (2001) is shown to include all models of the form used by King and Watson (1998) and Klein (2000), which permits any number of lags,...