持久冲击与中国经济增长的波动

文章依据一个内在逻辑一致的统计程序考察了1952~2003年间中国实际GDP序列的数据生成过程。发现中国实际GDP序列遵循一个带漂移的随机游走,因而它有一个随机波动的长期趋势;进一步的分析还揭示了长期趋势的波动幅度不小于短期周期性波动的幅度。这些事实在理论上意味着产出序列增长趋势的变化和它经常偏离趋势的运动共同构成了中国产出序列的波动。因此,有理由相信来自供给方面的持久冲击是导致中国经济波动不可忽视的重要原因。     

Labor Supply by Farm Operators Under “Decoupled” Farm Program Payments

As part of 1996 legislation, the U.S. began paying farmers production flexibility contract payments designed to be somewhat decoupled from current production decisions. In the labor-leisure model, decoupled payments would be expected to only have a wealth effect, but coupled payments would be expected to have both a substitution and a wealth effect. In this paper, the impacts of the decoupled payments and other government payments on both farm and off-farm labor allocations for farm operators are considered using data from the Agricultural Resource Management Survey (ARMS). Results indicate that government payments tend to increase the hours operators work on their farm and decrease the hours they work off the farm. This is true whether the payments come from programs which tie payments to current year production, or not.JEL Classification: D13, J22, Q12, Q22The authors are agricultural economists with the Economic Research Service (USDA). The views expressed here do not necessarily represent the views of the U.S. Department of Agriculture.     

Partitioned difference families and almost difference sets

Partitioned difference families (PDFs) were first studied by Ding and Yin in conjunction with the construction of constant composition codes (CCCs). In 2008, Yin et al. presented the constructions of a number of infinite classes of PDFs based on known difference sets in GF(q). In this paper, we further investigate the constructions of PDFs by using known almost difference sets in GF(q), and establish some recursive constructions of PDFs. As their applications, we also get a number of perfect difference systems of sets (DSSs) over Z_q² with q odd prime.     

论人口老龄化程度城乡差异的转变

在中国人口老龄化过程中,农村老年人口比例日益高于城市,这是否是中国人口老龄化过程中的特有现象?本文对中国和其他国家人口老龄化过程中城乡人口老龄化的差异进行了比较研究。结果表明,在人口老龄化过程中,许多国家普遍地表现出农村人口老龄化程度高于城市的特点,即城乡倒置明显。进一步研究表明,人口老龄化城乡倒置只是人口老龄化过程中的一个阶段,它不会长期持续。当社会经济发展达到一定水平,大规模的城乡人口迁移基本完成,城市化水平大幅提高,人口因素发生改变时,人口老龄化程度农村高于城市的城乡倒置状况将发生转变,即城市老年人口比例最终将超过农村。     

低生育水平下我国生育率转变影响机制的地区差异——来自90年代省级面板数据的经验研究

本文利用我国1990—2000年各地区总和生育率、社会经济发展水平和计划生育执行力度的面板数据,分别对东部特大城市、东部地区、中部地区和西部地区进行了实证分析。发现：计划生育政策对各地区生育率的降低都起到了重要的作用;同时,东部地区（包括特大城市）较高的经济、社会发展水平显著的降低了总和生育率,而经济较为落后的中、西部地区,这种作用不明显。     

老年人消费状况及其性别差异——以浙江省为例

在浙江省,无论城乡,老年人的消费状况均存在着显著的性别差异.表现在:女性老年人的月消费总支出低于男性;“饮食/食品”和“居住(房屋水电)”等最基本的生活消费支出比例往往高于男性;医疗月均费用少于男性,而医疗费占总消费支出的比例却高于男性;有人情往来的比例比男性略高,而支出均值却比男性低;对子女经济支持的均值低于男性、承受力弱于男性;低消费人群的比例显著大于男性,而中、高消费人群的比例却明显低于男性;对月最低生活费的评价均值低于男性;持较低评价值的比例多于男性,持较高评价值的比例少于男性;在经济上更感到拮据和困难等等.这些情况均表明:浙江省女性老年人的消费水平显著低于男性老年人.同时,由恩格尔系数反映出,女性老年人的生活水平也不如男性老年人.这就再次说明了:改善女性老年人的生活状况应该“成为政策行动的一个优先领域”.     

论罗尔斯正义概念的多重维度

在西方思想史探讨正义概念的基础上,罗尔斯指出正义是社会制度的首要价值。在古典自由主义传统基础上和设定的背景中,超越古典契约论,从道德人出发,确定了正义的自由平等权利的基本内涵。从原初状态和无知之幕的理论预设出发,在两个差别原则和优先性原则中,罗尔斯向我们展示了理解正义概念的多重维度。作为现代自由主义代表的罗尔斯的正义观遭遇来自古典自由主义和社群主义的批评,在此基础上,罗尔斯的回应也进一步丰富了理解其正义概念的维度。     

Rapid penalized likelihood-based outlier detection via heteroskedasticity test

Outlier detection is fundamental to statistical modelling. When there are multiple outliers, many traditional approaches in use are stepwise detection procedures, which can be computationally expensive and ignore stochastic error in the outlier detection process. Outlier detection can be performed by a heteroskedasticity test. In this article, a rapid outlier detection method via multiple heteroskedasticity test based on penalized likelihood approaches is proposed to handle these kinds of problems. The proposed method detects the heteroskedasticity of all data only by one step and estimate coefficients simultaneously. The proposed approach is distinguished from others in that a rapid modelling approach uses a weighted least squares formulation coupled with nonconvex sparsity-including penalization. Furthermore, the proposed approach does not need to construct test statistics and calculate their distributions. A new algorithm is proposed for optimizing penalized likelihood functions. Favourable theoretical properties of the proposed approach are obtained. Our simulation studies and real data analysis show that the newly proposed methods compare favourably with other traditional outlier detection techniques.     

Theoretical L-moments and TL-moments using combinatorial identities and finite operators

Moments have been traditionally used to characterize a probability distribution. Recently, linear moments (L-moments) and trimmed L-moments (TL-moments) are appealing alternatives to the conventional moments. This paper focuses on the computation of theoretical L-moments and TL-moments and emphasizes the use of combinatorial identities. We are able to derive new closed-form formulas of L-moments and TL-moments for continuous probability distributions. Finally, closed-form formulas for the L-moments for the exponential distribution and the uniform distribution are also obtained.     

古代中国与印度和希腊逻辑推论比较研究

逻辑学是全人类共同的，逻辑体系则带有时代、民族和个人的特点。分析世界古代三大逻辑，既要关注它们的共同点，但更应认识它们的差异性。文章在分析三大逻辑特征的基础上，论述了古代中国与印度和希腊逻辑推论的差异性，以及这种差异性对民族文化发展产生的影响。