分块矩阵的初等变换及其应用

本文讨论广义初等矩阵给出的分块矩阵初等变换及其在矩阵行列式、矩阵求逆、矩阵相似及特征多项式等方面应用.     

非负幂等交换半环上矩阵可逆的几个等价条件

本文给出了判断非负幂等交换半环上的矩阵可逆的几个等价条件     

适应金融市场环境 提升风险管理能力

进入新的五年计划时期，中国金融市场化环境已经并将继续发生新的深刻变化，包括利率和汇率市场化的进程不断加快，在此形势下，政府、银行和企业都面临一个更好地转变外部宏观金融市场环境，深入培育市场，更好地适应利率市场化和人民币汇率市场化的任务，只要积极主动应对，构建明晰的金融风险管理框架、提升风险计量与管理技术、方法、手段、工具，有效管理利率汇率风险，才能促进商业银行和全社会整体资金效益的提高和企业的可持续发展。     

Komplexität erfolgreich steuern — 27. Österreichischer Controllertag in Wien

Ohne Zusammenfassung     

China＇s Regional Disparity and Its Policy Responses

The fruits of China＇s rapid economic development over the 3 decades have not been distributed fairly across different regions. Using data from a sample of 815 Chinese listed firrns during 1998-2004, our error-correction investment model showes evidence of different financial constraints on firms＇ investment in different regions. We argue that China＇s regional development policies have contributed greatly to the regional inequalities. To control the rising inequality, China has shifted its focus from the coast to the interior regions. However, it is becoming increasingly difficult for the government to direct the economy, as market mechanisms now have afar greater influence on the economy than the government does. The people-centered approach of the current leadership has meant that substantial attention has been placed on regional development disparities in an attempt to build a ＂harmonious society. ＂ China needs further extensive reforms if all the measures for reducing regional disparity are to be effective.     

A generalization of Condorcet’s Jury Theorem to weighted voting games with many small voters

We extend Condorcet’s Jury Theorem (Essai sur l’application de l’analyse à la probabilité des décisions rendues à la pluralité des voix. De l’imprimerie royale, 1785) to weighted voting games with voters of two kinds: a fixed (possibly empty) set of ‘major’ voters with fixed weights, and an ever-increasing number of ‘minor’ voters, whose total weight is also fixed, but where each individual’s weight becomes negligible. As our main result, we obtain the limiting probability that the jury will arrive at the correct decision as a function of the competence of the few major players. As in Condorcet’s result the quota q = 1/2 is found to play a prominent role. I wish to thank Maurice Koster, Moshé Machover, Guillermo Owen and two anonymous referees for helpful comments.     

Background Risk and the Performance of Insurance Markets under Adverse Selection

Background risk can influence the performance of insurance markets that must deal with adverse selection when applicants are risk vulnerable, since they are more averse to bearing the insurable risk as a result of their exposures to background risk. We show that background risk always results in a lower deductible for the incentive constrained contract, and that a broader range of markets attains the stable sequential equilibrium cross-subsidized pair of separating contracts. We conclude that background risk always improves the performance of markets for coverage against (insurable) foreground risks that must deal with adverse selection. We also find, however, that these improvements are never sufficient to offset the cost to insureds of bearing the background risk.