The Minimal Entropy Martingale Measures for Exponential Additive Processes

In this paper, we will consider exponential additive processes as a financial market model. Under a mild condition, we will determine the minimal entropy martingale measures (MEMMs) for the exponential additive processes. To this end, we will prepare several results on the exponential moment of additive processes and integrals based on them. As an application of our result, we will deduce optimal strategy for exponential utility maximization problem. We will also investigate our result through several examples, such as time-dependent versions of double Poisson model, Merton model and Kou model.     

经济学的理性假设辨析

理性历来是经济学研究秉持的最基本的行为假设,然而自从其概念诞生以来,经济学家们对它的理解与解释却众说纷纭。理性的框架应界定为:利己性、最优化与偏好一致性。对理性假设应该采取秉持实证主义思想,维持理性假设的态度与措施;当理论与现实矛盾时,谨慎地适当地扩展理论模型或环境假设,扩展的底限是维持理性的内在一致性,上限则取决于理论的一般性与现实性的权衡。     

Ross risk vulnerability for introductions and changes in background risk

We present two theorems that provide necessary and sufficient conditions for an expected utility maximizer to become more risk averse in the sense of Ross with respect to bearing a foreground risk after the introduction of any independent fair or unfair additive background risk. We call these decision makers Ross risk vulnerable, and show that Ross decreasing absolute risk aversion and Ross decreasing absolute prudence are jointly sufficient for Ross risk vulnerability. Restrictions on utility necessary and sufficient for Ross risk vulnerability with respect to stochastic dominance deteriorations of an existing background risk are also presented. Our analysis concludes with applications of Ross risk vulnerability.     

Does self-regulation work? Experimental evidence of the reputational incentives of Self-Regulatory Organizations

Self-regulation (SR) is a common way of enforcing quality in markets (such as banking, financial services and several professions) and in a variety of public and private organizations. We provide experimental evidence of the reputational incentives of self-regulatory organizations (SROs) to publicly disclose versus cover-up fraud in an incomplete information environment. We find that observed behaviour is generally consistent with Bayesian equilibrium when subjects are informed about the relative likelihood of fraud detection by a ‘vigilant’ versus a ‘lax’ SRO type. In particular, a fraud disclosure equilibrium is supported when subjects are informed that the ‘vigilant’ SRO is more likely to detect fraud; otherwise, a cover-up equilibrium is supported. However, when subjects are not informed about the relative likelihood of fraud detection by the SRO types (as expected in real SR situations), no equilibrium is strongly supported. Our results suggest that in practice, the reputation-based incentives for effective SR may be inherently ambiguous and weak.     

消减城乡公共产品供给差异的策略——基于政治支持差异假设的探视

本文认为导致城乡公共产品供给差异的根本原因是地方政府官员根据不同主体能够给予的政治支持做出的理性选择。文章强调了政治支持差异对地方官员行为的影响,并把上级政府、城市居民和农村居民的政治支持纳入一个统一的分析框架,分析了地方官员从不同主体获得的政治支持权重大小顺序,给出了其最优策略的均衡条件。如果要实现基本公共产品均等化目标,则需优化政治支持结构。     

Asymptotic analysis for optimal investment and consumption with transaction costs

We consider an agent who invests in a stock and a money market and consumes in order to maximize the utility of consumption over an infinite planning horizon in the presence of a proportional transaction cost . The utility function is of the form U(c) = c^1-p/(1-p) for p > 0, . We provide a heuristic and a rigorous derivation of the asymptotic expansion of the value function in powers of , and we also obtain asymptotic results on the boundary of the no-trade region.Received: July 2003, Mathematics Subject Classification (1991): 90A09, 60H30, 60G44JEL Classification: G13Work supported by the National Science Foundation under grants DMS-0103814 and DMS-0139911.     

Jevons's Theory of Political Economy and the ‘Marginalist Revolution’ *

Very many statements have been made about the (non-)existence and characterisation of the ‘marginal revolution’ but it is urged here that detailed study of the relevant texts is far more valuable than the making of grand statements about such matters. In particular, a close reading of Jevons's Theory of Political Economyis proposed as an antidote to over-easy generalisation. Jevons by no means rejected all elements of classical theory. He did not propose a catallatic revolution; he attributed such an emphasis to earlier authors and himself stressed the role of production. It is shown that Jevons was very aware of the necessarily general equilibrium nature of his theory but that he was simply not able to cope with it satisfactorily; it is suggested that this explains, at least in part, his fluctuating and apparently inconsistent statements relating utility and labour to value. Jevons certainly attempted to sketch a complete marginal productivity theory of distribution, even if he was far from successful in providing one.     

Reviewing Oates' insights in a repeated game setting

This paper analyzes the optimal assignment of public good policies to layers of a federal system in a repeated game setting. Under a centralized regime, public goods are financed jointly across regions, and a federal legislature decides on the regional quantities. Under a decentralized regime, public goods are financed locally, and governments play a non-cooperative provision game. We find that a centralized (decentralized) regime is more likely to provide the efficient public good policies in case spillovers are small (large). Received: September 2003, Accepted: October 2004 JEL Classification: H11, H41 I wish to thank Clemens Fuest, Anke Kessler, Christoph Lülfesmann, and an anonymous referee for valuable comments on this paper. Financial support by the DFG (SPP 1142) is gratefully acknowledged.     

中国扩大进口中高档消费品可行性分析

目前中高档消费品已成为消费升级的重要对象",十二五"规划纲要首次提出要适当扩大消费品进口。基于科学发展观、全球新竞争理念及全新开放战略的"顶层设计",通过对扩大进口中高档消费品的理念、福利及条件等研究与分析后发现,中国具备扩大进口中高档消费品的条件,扩大进口中高档消费品是关乎国民福利的重要举措。     

A comparison of the estimates of expected utility and non-expected-utility preference functionals

This paper extends the literature on the estimation of expected utility and non-expected-utility preference functionals (and the consequent exploration of the superiority of non-expected-utility over expected utility preference functionals) to a comparison of two different ways (pairwise choice and complete ranking) of experimentally obtaining data on such preferences. What is revealed is that the magnitude of the subject error is clearly conditional on the elicitation method used and, rather alarmingly, that the preference functional apparently employed by the subject may also be conditional on the elicitation method.