Equilibrium in a reinsurance market with short sale constraints

Summary. This paper deals with the existence of equilibrium in a dynamic reinsurance market with short sale constraints, driven by a marked point process, as studied in Bernis and Jouini (2001). We use the set of reinsurance treaties as consumption set, which is the positive orthant of some Banach lattice that can be identified to a space of martingales, . The properness of preferences is a key assumption for us to prove the existence of an equilibrium. We provide a sufficient condition for the preferences to be proper in term of loading factor of the reinsurance premium. Received: June 15, 2000; revised version: May 17, 2001     

世界丁辛醇市场分析

本文介绍了国内外丁辛醇的供需及消费情况,2005年丁辛醇生产能力达到约380万t/a.     

对决策支持系统的认识

管理的核心是“决策”。决策支持系统作为一种新兴的信息技术,能够为企业提供各种决策信息及诸多问题的解决方案,从而减轻了管理者从事低层次信息处理和分析的负担,专注于最需要决策的工作,提高决策的质量和效率。决策支持系统主要应用于销售支持、客户分析、财务分析、企业分析和市场研究等方面,对企业决策至关重要。     

借鉴美国经验规范和发展我国货币市场基金

美国货币市场发达的主要原因在于可供交易的货币市场工具丰富,结构层次化、利率市场化,参与广泛等。我国货币市场规模小、品种单一,市场基础设施不完善,缺少相应的组织结构和制度保障,与美国货币市场化相去甚远。应借鉴美国的经验发展我国货币市场基金,加强货币市场基础设施建设,创新金融产品,加强货币市场基金风险管理,真正发挥货币市场基金作为现金管理工具的功能。     

Sovereign risk assessment and agency credit ratings

Sovereign ratings are gaining importance as more governments with greater default risk borrow in international bond markets. However, while the ratings have proved useful to governments seeking market access, the difficulty of assessing sovereign risk has led to agency disagreements and public controversy over specific rating assignments. Recognising this difficulty, the financial markets have shown some scepticism toward sovereign ratings when pricing issues.     

On the use of measure-valued strategies in bond markets

We propose here a theory of cylindrical stochastic integration, recently developed by Mikulevicius and Rozovskii, as mathematical background to the theory of bond markets. In this theory, since there is a continuum of securities, it seems natural to define a portfolio as a measure on maturities. However, it turns out that this set of strategies is not complete, and the theory of cylindrical integration allows one to overcome this difficulty. Our approach generalizes the measure-valued strategies: this explains some known results, such as approximate completeness, but at the same time it also shows that either the optimal strategy is based on a finite number of bonds or it is not necessarily a measure-valued process.Received: November 2002, Mathematics Subject Classification: 60H05, 60G60, 90A09JEL Classification: G10, E43The first author gratefully acknowledges financial support from the CNR Strategic Project Modellizzazione matematica di fenomeni economici. We thank professors A. Bagchi, R. Douady and J. Zabczyk for helpful discussions. A special thanks goes to professors T. Björk, Y. Kabanov and W. Schachermayer for comments and suggestions which contributed to improve the final version of this paper.     

A geometric approach to portfolio optimization in models with transaction costs

We consider a continuous-time stochastic optimization problem with infinite horizon, linear dynamics, and cone constraints which includes as a particular case portfolio selection problems under transaction costs for models of stock and currency markets. Using an appropriate geometric formalism we show that the Bellman function is the unique viscosity solution of a HJB equation.Mathematics Subject Classification (1991): 60G44JEL Classification: G13, G11This research was done at Munich University of Technology supported by a Mercator Guest Professorship of the German Science Foundation (Deutsche Forschungsgemeinschaft). The authors also express their thanks to Mark Davis, Steve Shreve, and Michael Taksar for useful discussions concerning the principle of dynamic programming.     

Understanding the Implied Volatility Surface for Options on a Diversified Index

This paper describes a two-factor model for a diversified index that attempts to explain both the leverage effect and the implied volatility skews that are characteristic of index options. Our formulation is based on an analysis of the growth optimal portfolio and a corresponding random market activity time where the discounted growth optimal portfolio is expressed as a time transformed squared Bessel process of dimension four. It turns out that for this index model an equivalent risk neutral martingale measure does not exist because the corresponding Radon-Nikodym derivative process is a strict local martingale. However, a consistent pricing and hedging framework is established by using the benchmark approach. The proposed model, which includes a random initial condition for market activity, generates implied volatility surfaces for European call and put options that are typically observed in real markets. The paper also examines the price differences of binary options for the proposed model and their Black-Scholes counterparts. Mathematics Subject Classification: primary 90A12; secondary 60G30; 62P20 JEL Classification: G10, G13     

Long-run matching relationship in the Japanese labor market

This paper investigates the long-run relationship among new hiring, unemployment (job seekers), and unfilled vacancies in Japan, using an annual panel data on 47 prefectures for 1972-1999. We find that these three variables are I(1) processes, and are cointegrated in our panel data. Further, we estimate the panel cointegration equation derived from a Cobb-Douglas matching function by the heterogeneous fully modified OLS and heterogeneous dynamic OLS. The estimation results reveal that conventional within estimates could have non-negligible biases.First version received: November 2002/Final version received: October 2003All correspondence to Shigeki Kano. The authors are grateful to the associate editor and two anonymous referees of this journal for helpful comments. Doctor Stephen J. Turnbull (University of Tsukuba) is also acknowledged for correcting English errors in this paper. Remaining errors are due to the authors. The data set and GAUSS programming code used in this paperare available upon request.     

The "Invisible Hand"

The argument of the "Invisible Hand" is that the system of free enterprise benefits society in general even though it is not the aim of any particular economic agent to do that. This article proposes an analysis of why this is so. The key is that the morality of the market forbids only force and fraud; it does not require people to do good to others. Nevertheless, when all transactions are voluntary to both parties, that is exactly what we can expect to happen. This is both because the sum of the benefits of innumerable transactions, which are beneficial to both parties, is very great, but also and especially because of Positive Externalities. People use the particular products and services they get in market exchanges in ways that benefit others in ways not at all foreseen by the agents to those transactions at the time. These externalities range from the benefits of invention and ingenuity to the exercise of charity and philanthropy, all of which flourish in developed capitalist societies.