For homothetic time and state separable preferences, the coefficient of relative risk aversion is equal to the reciprocal of the elasticity of intertemporal substitution. This paper shows that, when the growth rate of consumption is independent and identically distributed, asset pricing models based upon preferences in which the coefficient of relative risk aversion and the elasticity of intertemporal substitution are no longer linked do not have more explanatory power. Further, in these stochastic environments, estimates of the coefficient of relative risk aversion in the standard preferences are measures of the true coefficient of relative risk aversion and not the elasticity of intertemporal substitutions. These results are fairly accurate descriptions of economies calibrated using United States annual data.

Abstract This article reconsiders the question of optimal labour income taxes for the very rich in the context of a flexible moral hazard model. In this setting, risk is not exogenous. Rather, each agent can affect the probabilities of all possible income outcomes by allocating a fixed time endowment across a variety of distinct tasks. I prove that the optimal income tax rates on high-end earners and the optimal Pareto tail index of the pre-tax labour income distribution are both endogenously determined by agent preferences. In particular, a society with less risk-averse agents will find it optimal to impose a lower tax rate on the rich, even though its members’ choices give rise to a smaller Pareto right tail index. In contrast, this kind of negative co-movement between inequality and optimal tax rates is a suboptimal response in the classical Mirrlees (1971)–Diamond (1998)–Saez (2001) setup to changes in the exogenous distribution of skills.

This paper shows that there is more scope for a borrower to engage in a sustainable infinite debt rollover (a “Ponzi scheme”) when interest/growth rates are stochastic. In this context, I prove that the relevant “r vs. g” comparison uses the yield r long to an infinite‐maturity zero‐coupon bond. I show that r long is lower than the risk‐neutral expectation of the short‐term yield when it is variable, and that r long is close to the minimal realization of the short‐term yield when it is highly persistent. The paper applies these results to illustrative heterogeneous agent dynamic stochastic general equilibrium models to obtain similarly weakened sufficient conditions for the existence of public debt bubbles.

Abstract Since the collapse of the Bretton Woods monetary system, the monies of the developed world have been unbacked by any formal promise of convertibility. Yet, inflation has typically undershot, not overshot, central bank targets over the past couple decades. The low, while generally positive, inflation rate has (more arguably) been associated with low output and low growth. In this article, I consider these observations through the lens of a class of representative agent rational expectations models with nominal (price-setting) frictions and the possibility of firm entry/exit. I show that for any level of nominal frictions (no matter how small) and for any monetary policy rule that satisfies a set of weak restrictions, there is a large set of equilibria that exhibit permanently low inflation, low output, and low nominal interest rates. These equilibria can only exhibit positive long-run inflation if growth is low and the specification of nominal frictions (i.e. the Phillips curve) takes an unconventional but nonetheless empirically plausible form.

This essay discusses the structure and governance of the Federal Reserve System in light of the many changes in its activities over the past thirty years. Based on this analysis, it argues in favor of four specific reforms: clarification of Congressional expectations for the system; enhanced Federal Reserve Board of Governors transparency with respect to its oversight of the Reserve Banks; stripping monetary-policy votes from the President of the Federal Reserve Bank of New York and the Boards of Directors of the Reserve Banks; and the initiation of a public conversation about redesigning the Federal Reserve as a unified public entity. (JEL D72, E44, E52, E58, G21, G28)

In this paper, I consider a dynamic economy in which a government needs to finance a stochastic process of purchases. The agents in the economy are privately informed about their skills, which evolve stochastically over time; I impose no restriction on the stochastic evolution of skills. I construct a tax system that implements a symmetric constrained Pareto optimal allocation. The tax system is constrained to be linear in an agent's wealth, but can be arbitrarily nonlinear in his current and past labor incomes. I find that wealth taxes in a given period depend on the individual's labor income in that period and previous ones. However, in any period, the expectation of an agent's wealth tax rate in the following period is zero. As well, the government never collects any net revenue from wealth taxes. Copyright The Econometric Society 2005.

ABSTRACT For homothetic time and state separable preferences, the coefficient of relative risk aversion (CRRA) is equal to the reciprocal of the elasticity of intertemporal substitution (EIS). This paper shows that, when the growth rate of consumption is i.i.d., asset pricing models based upon preferences in which the CRRA and the EIS are no longer linked do not have more explanatory power. Further, in these stochastic environments, estimates of the CRRA in the standard preferences are measures of the true CRRA and not the EIS. These results are fairly accurate descriptions of economies calibrated using United States annual data.

For homothetic time and state separable preferences, the coefficient of relative risk aversion (CRRA) is equal to the reciprocal of the elasticity of intertemporal substitution (EIS). This paper shows that, when the growth rate of consumption is i.i.d., asset pricing models based upon preferences in which the CRRA and the EIS are no longer linked do not have more explanatory power. Further, in these stochastic environments, estimates of the CRRA in the standard preferences are measures of the true CRRA and not the EIS. These results are fairly accurate descriptions of economies calibrated using United States annual data.