It is often argued that a rational bubble, because it is positive, must increase the price of a stock. This argument is not valid in general: as soon as bubbles affect interest rates, the fundamental value of a stock depends on whether or not a bubble is present. The existence of a rational...

Arguing that total consumer wealth is unobservable, we invert the (approximate) consumption function to reconstruct, in a world with Kreps-Porteus generalized isoelastic preferences, i) the wealth that supports the agents’ observed consumption as an optimal outcome and ii) the rate of return...

In a world in which consumers correctly expect that both Ricardian and non-Ricardian policy regimes are possible in the future, the fiscal theory of the price level is valid, yet the price is indeterminate. This result does not rely on imposing that the initial stock of nominal bonds be strictly...

The purpose of this note is to simply point out that the multiplicity, intrinsic of course to the presence of non-convexities, characterizes the models of growth with external increasing returns which have been studied recently, and, more importantly, to show that the many competitive equilibria...

This paper reconsiders the determination of asset returns in a model with Kreps-Porteus generalized isoelastic preferences where returns appear governed on the basis of Euler equations, by a combination of the two most common measures of risk -- covariance with the market return and covariance...

Endogenous labor supply decisions are introduced in an equilibrium model of limited insurance against idiosyncratic shocks. Unlike in the standard case with exogenous labor (e.g. [Aiyagari, S.R., 1994. Uninsured idiosyncratic risk and aggregate saving. Quarterly Journal of Economics 109, 659–684;...

This paper examines how aversion to risk and aversion to intertemporal substitution determine the strength of the precautionary saving motive in a two-period model with Selden/Kreps-Porteus preferences. For small risks, we derive a measure of the strength of the precautionary saving motive which...

This Paper examines how aversion to risk and aversion to intertemporal substitution determines the strength of the precautionary saving motive in a two-period model with Kreps-Porteus preferences. For small risks, we derive a measure of the strength of the precautionary saving motive, which...

In a dynamically efficient economy, can a government roll its debt forever and avoid the need to raise taxes? In a series of examples of economies with zero growth, this paper shows that such Ponzi games may be infeasible even when the average rate of return on bonds is negative, and may be...