How can a particular allocation and prices be implemented? Under what conditions does a policy deliver a unique competitive equilibrium? How many degrees of freedom there are in the determination of the policy variables, or how many are the instruments of policy? In this paper we analyze a...

The usual conclusion in the literature is that sunspots reduce welfare because of the agents' risk aversion. However, if sunspots can lead to escape from an inferior steady state (poverty trap), this conclusion does not necessarily hold. Escaping trajectories can have much higher welfare than...

In recent years, the learnability of rational expectations equilibria (REE) and determinacy of economic structures have rightfully joined the usual performance criteria among the sought-after goals of policy design. Some contributions to the literature, including Bullard and Mitra (2001) and...

We study how the use of judgement or add-factors in macroeconomic forecasting may disturb the set of equilibrium outcomes when agents learn using recursive methods. We isolate conditions under which "exuberance equilibria" exist in standard macroeconomic environments. These equilibria may...

It is well known that if there are mild sector-specific externalities, then the steady state of the standard two-sector real business cycle model can become indeterminate and endogenous business cycles can arise. We show that this result is not robust to the introduction of standard...