Polyhedral Combinatorics in Combinatorial Optimization

Polyhedral combinatorics is a subarea of combinatorial optimization of increasing practical importance. It deals with the application of the theory of linear systems and linear algebra to combinatorial problems. The paper is not intended as a survey on polyhedral combinatorics but it reviews some of the main concepts and proof techniques.     

The Bell Curve in Psychological Research and Practice: Myth or Reality?

The expression “the bell curve” designs both a kind of statistical distribution and the title of a famous and controversial book by Herrnstein and Murray. The first is so attractive that the second refers to it to give more credibility to its questionable theories on intelligence. The point is that, during the 20th century, the bell curve has assumed a more and more important role in psychological research and practice and have become both a reality and a myth. In the first case (reality) we can assist to appropriate applications of a real useful statistical concept. In the second (myth) we can have two kinds of attitudes: one attitude is typical of those researchers who search for normality in all their data and variables, just as Parsifal used to search for the Holy Graal (we call this “the Parsifal attitude”); the other is typical of those researchers who give normality for granted and act as if it were a Platonic Idea (we call this “the Plato attitude”). The article discusses the role of the normal distribution in psychological research and practice and shows how it can be dangerous to treat the bell curve as a God or an Idol.     

倾销幅度测算中的偏颇之处

倾销幅度测算是裁定倾销以及实施反倾销措施的依据和基础。然而,具体操作过程中存在的偏颇之处,使得调查结果总是倾向发现“倾销幅度”,从而裁定倾销存在。本文以倾销幅度测算过程中的不合理之处为分析对象,举例说明了在很多情况下,原本不存在的倾销行为,是如何在现行的规定下被测算出了“倾销幅度”。     

Convenient estimators for the panel probit model: Further results

Bertschek and Lechner (1998) propose several variants of a GMM estimator based on the period specific regression functions for the panel probit model. The analysis is motivated by the complexity of maximum likelihood estimation and the possibly excessive amount of time involved in maximum simulated likelihood estimation. But, for applications of the size considered in their study, full likelihood estimation is actually straightforward, and resort to GMM estimation for convenience is unnecessary. In this note, we reconsider maximum likelihood based estimation of their panel probit model then examine some extensions which can exploit the heterogeneity contained in their panel data set. Empirical results are obtained using the data set employed in the earlier study. Helpful comments and suggestions by Irene Bertschek and Michael Lechner are gratefully acknowledged. This paper has also benefited from comments by two anonymous referees and from seminar participants at the Center for Health Economics at the University of York. Any remaining errors are the responsibility of the author.     

中期财务报告准则的比较研究

为提高上市公司会计信息质量，更好地保护投资者利益，2001年11月，财政部发布了《企业会计准则——中期财务报告》。鉴于美国是实行中期报告制度最早的国家，其制度也相对完善，本文拟将我国中期财务报准则同美国的相关准则及国际会计准则IAS34作粗浅的比较分析。通过比较分析，借鉴国外准则之长处，有利于推动我国中期报告理论和实务的发展。     

山区高速公路选线设计的探讨

对在公路建设中如何贯彻可持续发展战略进行了简要论述,阐明了作者的观点;介绍山区公路的特点,对山区公路传统的选线原则提出了不同的看法;结合常德至吉首高速公路湘西段,从整体把握路线方案,平、纵指标分析,局部方案比选等方面谈山区公路选线。     

Measuring Inequalities without Linearity in Envy: Choquet Integrals for Symmetric Capacities

The (generalized) Gini indices rely on the social welfare function of a decision maker who behaves in accordance with Yaari's model, with a function f that transforms frequencies. This SWF can also be represented as the weighted sum of the welfare of all the possible coalitions in the society, where the welfare of a coalition is defined as the income of the worst-off member of that coalition. We provide a set of axioms (Ak) and prove that the three following statements are equivalent: (i) the decision maker respects (Ak), (ii) f is a polynomial of degree k, (iii) the weight of all coalitions with more than k members is equal to zero. Journal of Economic Literature Classification Number: D63.     

Bayesian assessment of dimensionality in reduced rank regression

We consider Bayesian inference about the dimensionality in the multivariate reduced rank regression framework, which encompasses several models such as MANOVA, factor analysis and cointegration models for multiple time series. The fractional Bayes approach is used to derive a closed form approximation to the posterior distribution of the dimensionality and some asymptotic properties of the approximation are proved. Finite sample properties are studied by simulation and the method is applied to growth curve data and cointegrated multivariate time series.     

浅析资本弱化与外资避税

随着现代资本结构理论的发展,国内外企业都在学习如何在实务中对其加以灵活应用,使企业价值最大化.资本弱化就是这样一种应用,其目的在于企业通过资本结构安排,改变其纳税义务,起到避税的作用.目前,来自发达国家的外资企业在这一避税手法的使用上已达到了十分成熟的阶段,再加上我国现行税制框架尚未对资本弱化进行识别、规范和控制,造成了我国大量的税收利益流失.另外,在我国已逐渐认识到问题的紧迫性的情况下,如何进行监管和控制也是一个很大的技术难题.     

城市公交行业顾客满意度测评及其提升对策——以合肥市为例

城市公交作为城市经济运转的动脉,已经成为国内城市发展规划中的重中之重。然而,目前在城市公交行业占主体地位的国有公交企业却亟待提高营运效益,增强企业活力,以摆脱经营上的困境。立足于安徽省省会城市合肥市的公交行业,通过实证研究与规范研究相结合的方式,针对城市公交行业的顾客满意度测评及其提升对策问题进行了较为深入的探讨。