Einzelbesprechungen

Ohne ZusammenfassungÜbersetzt von Gerhard Tintner, WienÜbersetzt von Ragnar Nurkse, z. Zt. Wienaus dem Italienischen übersetzt von Dr. Hans Fried, WienÜbersetzt von Paul Brüll, Wien.Aus dem Italienischen übersetzt von Dr. Hans Fried.     

Efficiency in coalition games with externalities

A natural extension of superadditivity is not sufficient to imply that the grand coalition is efficient when externalities are present. We provide a condition, analogous to convexity, that is sufficient for the grand coalition to be efficient and show that this also implies that the (appropriately defined) core is nonempty. Moreover, we propose a mechanism which implements the most efficient partition for all coalition formation games and characterizes the resulting payoff division.     

Why Punish? Social reciprocity and the enforcement of prosocial norms

Recently economists have become interested in why people who face social dilemmas in the experimental lab use the seemingly incredible threat of punishment to deter free riding. Three theories with evolutionary microfoundations have been developed to explain punishment. We survey these theories and use behavioral data from surveys and experiments to show that the theory called social reciprocity in which people punish norm violators indiscriminately explains punishment best.JEL Classification: C91, C92, D64, H41 Correspondence to: Jeffrey P. CarpenterWe thank Carolyn Craven, Corinna Noelke and two referees for comments, and Middlebury College for financial assistance. In addition, Carpenter acknowledges the support of the National Science Foundation (SES-CAREER 0092953).     

Mean-Variance Preferences and Investor Behaviour

We study the comparative statics implications of mean-variance preferences for optimal portfolios. Specifically, we show that all risk-averse mean-variance investors raise their investment in a risky asset in response to a change in that asset's return distribution if and only if the change lowers both the mean and standard deviation of the return by the same percentage. Besides being of interest in its own right, our results allow us to compare some comparative statics implications and the expected utility and mean-variance models systematically.     

Optimal Retirement with Increasing Longevity

We develop an optimizing life‐cycle model of retirement with perfect capital markets. We show that longer healthy life expectancy usually leads to later retirement, but with an elasticity less than unity. We calibrate our model using data from the US and find that, over the last century, the effect of rising incomes, which promote early retirement, has dominated the effect of rising lifespans. Our model predicts continuing declines in the optimal retirement age, despite rising life expectancy, provided the rate of real wage growth remains as high as in the last century.     

私有化更有效率吗

本文对始自里根和撒切尔夫人主政时期的私有化浪潮提出了批评和质疑。本文认为,以解决政府失灵问题的私有化浪潮,可能导致更为严重的市场失灵问题。虽然在总体上私有企业比国有企业有更强的盈利能力,但这并不意味着私有企业比国有企业更有效率。即使能够证明私有企业比国有企业更有效率,也不能说私有化是可取的。     

You can't have a CGE recession without excess capacity

Simulations with dynamic, single country, CGE models typically imply that reductions in domestic demand, e.g. a cut in investment, generate increases in exports and reductions in imports facilitated by real depreciation. However, currently in the U.S. a large reduction in investment is occurring simultaneously with a contraction in exports and little movement in the real exchange rate. We show that to describe this situation it is necessary to drop the standard CGE assumption that capital is always fully employed in every industry. After introducing an excess capacity specification, we simulate the U.S. recession with and without the Obama stimulus package.