Harvesting to Extinction: Is It Socially Rational?

This paper presents a critique of the neoclassical view of the optimal use of renewable resources and offers an alternative view based on the method of classical thermodynamics. The presentation is forwarded via the issue of harvesting to extinction. Based on simple models, the traditional theory suggests that society would benefit from wiping out any renewable resource whose intrinsic growth rate, though positive, is smaller than the social rate of time preference. The latter is the rate society is using to discount its future benefits and costs. To bypass this ecologically implausible outcome, the simplistic assumptions have been modified in various ways. For example, either the costs or the benefits of harvesting have been made to depend on the stock of the resource as well as on the yield. The modifications offered make society less prone to wipe out resources intentionally, but they still disregard a more fundamental difficulty: The traditional theory is not consistent with the second law of thermodynamics; it describes a process that defies the second law, which no known system is able to be undergoing. No doubt, the theory should be challenged first and foremost on this ground, but none of the offered modifications is capable of annulling this inconsistency. A deeper change is needed because the social values of the resource as perceived by a society that behaves in manners consistent with the second law and as defined by the traditional theory necessarily differ. The paper identifies the socially consistent value and shows that harvesting to extinction is never optimal socially. Were society to follow the socially inconsistent value, it would always underestimate the importance of self-sustained resources. However, the unlikely refutability of the second law turns this possibility and the socially favored extinctions into arguable outcomes of an untenable theory rather than undesirable outcomes of a sound theory. Potentially growing renewable resources are wiped out in real life for various reasons, but when they are preyed to extinction, their unfortunate fate is an outcome of the dynamics of a socially unregulated system rather than a social objective coming to fruition. This revised version was published online in July 2006 with corrections to the Cover Date.     

The First Crisis of the Twenty-First Century-摘自《不确定的世界》第一章

On the evening of January 10, 1995, I stood on the Great Seal woven into the carpet of the Oval Office and swore to uphold the Constitution of the United States as Secretary of the Treasury. Confirmed earlier that day, I have been waiting all afternoon for the official document that would allow me to take the oath of office. Once the papers     

Consumption and risk sharing over the life cycle

A striking feature of U.S. data on income and consumption is that inequality increases with age. This paper asks if individual-specific earnings risk can provide a coherent explanation. We find that it can. We construct an overlapping generations general equilibrium model in which households face uninsurable earnings shocks over the course of their lifetimes. Earnings inequality is exogenous and is calibrated to match data from the U.S. Panel Study on Income Dynamics. Consumption inequality is endogenous and matches well data from the U.S. Consumer Expenditure Survey. The total risk households face is decomposed into that realized before entering the labor market and that realized throughout the working years. In welfare terms, the latter is found to be more important than the former.     

Risks for the Long Run: A Potential Resolution of Asset Pricing Puzzles

We model consumption and dividend growth rates as containing (1) a small long‐run predictable component, and (2) fluctuating economic uncertainty (consumption volatility). These dynamics, for which we provide empirical support, in conjunction with Epstein and Zin's (1989) preferences, can explain key asset markets phenomena. In our economy, financial markets dislike economic uncertainty and better long‐run growth prospects raise equity prices. The model can justify the equity premium, the risk‐free rate, and the volatility of the market return, risk‐free rate, and the price–dividend ratio. As in the data, dividend yields predict returns and the volatility of returns is time‐varying.     

Nested multiple imputation of NMES via partially incompatible MCMC

The multiple imputation of the National Medical Expenditure Survey (NMES) involved the use of two new techniques, both having potentially broad applicability. The first is to use distributionally incompatible MCMC (Markov Chain Monte Carlo), but to apply it only partially, to impute the missing values that destroy a monotone pattern, thereby limiting the extent of incompatibility. The second technique is to split the missing data into two parts, one that is much more computationally expensive to impute than the other, and create several imputations of the second part for each of the first part, thereby creating nested multiple imputations with their increased inferential efficiency.     

Strategic intergenerational bequests with stochastic convex production

Summary This note reconsiders the well-known model of strategic bequest/ altruistic growth, but with stochastic production satisfying a strong convexity condition: The probability that the next stock exceeds any given level is concave in investment. Existence of a Markov-stationary equilibrium consumption schedule, which is continuous and with all slopes in [0,1], is established. Under smooth data and interiority assumptions, this schedule is differentiable, and marginal consumption is in (0,1). This property allows for a rigorous and straightforward treatment of the equilibrium characterization problem.The author is grateful to Wolfgang Leininger for helpful discussions on the subject of this paper. This research work was carried out while the author was visiting C.O.R.E., Belgium and the University of Dortmund, Germany. The author wishes to thank both institutions for providing a great work environment as well as financial support from the projects Markets as Games and Marktstruktut und Gesamtwirtschaftliche Entwicklung, respectively.     

Asymmetric Regulation of Identical Polluters in Oligopoly Models

Studies of optimal second-best environmental regulation of identical polluting agents have invariably ignored potentially welfare-improving asymmetric regulation by imposing equal regulatory treatment of identical firms at the outset. Yet, cost asymmetry between oligopoly firms may well give rise to private as well as social gains. A trade-off is demonstrated for the regulator, between private costs savings and additional social costs when asymmetric treatment is allowed. Asymmetry is indeed optimal for a range of plausible parameter values. Further, it is demonstrated that for a broad class of abatement cost functions, there is scope for increasing welfare while keeping both total output and total emission constant. Some motivating policy issues are discussed in light of the results, including international harmonization and global carbon dioxide reduction.     

Children's responses to TV advertising: Product versus premium orientation

Attention has focused on a call for a ban on premium offers in children's television ads. Key considerations for proposing a ban was reflected in the FTC's statements regarding the confusion and difficulties of choice when the injection of a premium becomes the selling point rather than product merit. The sparsity of previous research in this area led to this exploration of television advertising viewing of different commercial content as it affects the “consumer learning process” of a child. This basically involves a continuum of learning, from the simplest recall of specific marketing-oriented elements such as identification of product or sponsor to the more complex level of understanding the use or value of a particular product or service. Trends noted in this study give additional insight to the marketing practitioner concerning the types of elements a child can assimilate and to the child's understanding of the message.