A note on the projection properties of Hadamard matrices obtained by the first Payley construction

We show that the projections on four factors of an arbitrary orthogonal array of strength 2 allow the estimation of main effects and two-factor interactions when all other effects are assumed to be zero, if those projections satisfy the bounds given by Weils theorem. The only exceptions are the Hadamard matrices of orders 16 and 24. A consequence is again the estimability of main effects and two-factor interactions for the projections on four factors of the first Payley construction for arbitrary run size.     

长春市中心区人口疏散规模估算评析与调控策略工程

分析了长春市中心区人居环境现状特征,以此为基础,从三个不同的角度,估算了人口疏散的规模,探讨了人口疏散的时空阶段及相应的调控对策。     

How many voters are needed for paradoxes?

Summary. This paper presents a general procedure for finding profiles with the minimum number of voters required for many important paradoxes. Borda's and Condorcet's classic examples are revisited as well as generalizations. Using Saari's procedure line, we obtain an upper bound for the minimum number of voters needed for a profile for which the Condorcet winner is not strictly top ranked for all weighted positional procedures. Also we give a simple upper bound on the minimum number of voters needed for a set of prescribed voting outcomes. In contrast to situations wherein small numbers of voters are needed, we consider paradoxes requiring arbitrarily large numbers of voters as well as large numbers of alternatives. Finally we indicate connections with statistical rank based tests. Received: April 18, 2001; revised version: May 25, 2001     

On the evolutionary edge of altruism: a game-theoretic proof of Hamilton’s rule for a simple case of siblings

We offer a game-theoretic proof of Hamiltons rule for the spread of altruism. For a simple case of siblings, we show that the rule can be derived as the outcome of a one-shot prisoners dilemma game between siblings.JEL Classification: A13, C70, D64Correspondence to: Oded Stark, ZEF, University of Bonn, Walter-Flex-Strasse 3, 53113 Bonn, GermanyWe are indebted to an anonymous referee and to Uwe Cantner for helpful comments and suggestions. Partial financial support from the National Institute on Aging (grant RO1-AG13037) and from the Humboldt Foundation is gratefully acknowledged.     

Distribution Dynamics of CO<Subscript>2</Subscript> Emissions

This paper uses nonparametric methods to examine the convergence in CO₂ emissions per capita on a sample of 100 countries for the period 1966–1996. Industrial countries show a convergence pattern. However, there is little evidence of convergence for the whole sample.     

关于人民币远期定价权问题的研究

本文通过静态及动态的两类模型对人民币远期定价权问题进行了研究。结果表明，我国人民币远期市场尚未摆脱境外NDF市场的影响，NDF市场仍是影响人民币远期定价的主要因素。而2005年8月以来我国外汇市场推出的各项改革措施，使得基于利率平价的定价机制开始在人民币利率的决定中发生作用；我国人民币远期市场定价机制尚未实现从基于预期的定价机制向利率平价的转变，我国银行间人民币远期市场尚未掌握人民币远期定价的主导权，但基于利率平价的人民币远期定价机制在人民币远期定价中所起的作用越来越显著。在此基础上，本文提出了相应的政策建议。     

On transaction efficiency and China’s Urban-Rural disparity

It is recommended for economists to examine China’s Urban-Rural disparity from the perspective of transaction efficiency, in that it can provide us with a systematic explanation to both the cases of different countries and development stages. China’s Urban-Rural disparity is special and virtually a demonstration of its special transaction efficiency structure. Exploration of China’s Urban-Rural disparity from such perspective indicates that, different from those in countries with a market economy, China’s case involves many exogenous and contrived factors. Therefore, the solutions are to improve the whole transaction efficiency in the economy, which includes eliminating its regionally unfavorable policies and institutions, and enforcing more favorable and regionally balanced institutional reforms. __________ Translated from Fudan Journal (复旦学报, Social Science Edition), 2006, (1) (in Chinese)     

控制权性质影响税收敏感性吗?——基于企业劳动力需求的检验

西方学者研究表明企业所得税是劳动力需求的重要影响因素,这一理论在中国是否适用?中国大部分上市公司为国有控股企业,这一特殊的制度背景是否会影响企业所得税与劳动力需求的关系?本文基于2007年企业所得税改革这一外生政策变化,在检验西方企业所得税与劳动力需求关系的理论在中国是否适用的基础上,就不同控制权的性质是否会影响企业劳动力需求的税收敏感性进行了检验。研究发现企业所得税税率降低和"就业税盾"增加提高了企业劳动力需求,但这种税率和"就业税盾"的变化对国有控股企业劳动力需求变化的影响要显著小于非国有控股企业。这表明税收是影响企业劳动力需求的重要因素,但国有控制权使得这种税收敏感性变弱。本文的研究结果不仅丰富了相关领域的国际学术文献,而且对我国就业政策的制定具有政策含义。     

论企业文化在塑造核心竞争力诸因素中的核心地位

本文借鉴7S模型分析了塑造企业核心竞争力的影响因素和途径,运用文献和案例论证了企业文化在塑造核心竞争力的各因素中居于核心地位,指出了塑造核心竞争力的途径是运用先进的企业文化培育和谐的7S体系。     

Two–step sequential sampling

Choosing the sample size in advance is a familiar problem: often, additional observations appear to be desirable. The final sample size then becomes a random variable, which has rather serious consequences.
Two such sample extension situations will be considered here. In the first situation, the observed sample variance determines whether or not to double the original sample size. In the second situation, the variances observed in two independent samples are compared; their ratio determines the number of additional observations.