中国各地区油菜生产率的增长及收敛性分析

运用基于DEA的Malmquist指数分析方法和省级油菜成本收益数据,对中国各地区油菜生产率的增长状况进行了实证分析,并将生产率进一步分解为技术进步和技术效率,在此基础上对全要素生产率地区间差距进行了绝对收敛和条件收敛检验。结果显示：1979—2005年中国油菜生产率平均增长率为-6％,技术进步为-5．8％,技术效率为-0．2％,生产率的下降主要是由技术退步所引起的;全国各油菜主产省的生产率不仅存在σ收敛,并且存在绝对β收敛和条件β收敛,其收敛速度分别为7．59％和8．93％,而收敛现象主要发生在20世纪80年代。     

近三十年国内新闻专业主义研究综述（1979～2009）

改革开放以来,国内学者对新闻专业主义的研究不断深入,但是通过对中国学术期刊数据库收录的近三十年研究成果调查发现：学者们对新闻专业主义的研究在内容上呈现分散、多元的格局,且主要以理论研究为主,其研究方式也偏重理论结合实际的个案研究,研究视野的深度和广度虽有明显进步,但仍存在学科运用单一、系统化研究不充分和重复性研究等问题。因此,国内学者应在今后新闻专业主义的研究中关注媒介融合下的新现象、新动态,并运用多学科知识来分析问题和不断拓展研究的视野与方法,以达到监督和推动媒介健康、有序发展的目的。     

A Spline‐Based Semiparametric Maximum Likelihood Estimation Method for the Cox Model with Interval‐Censored Data

Abstract. We propose a spline‐based semiparametric maximum likelihood approach to analysing the Cox model with interval‐censored data. With this approach, the baseline cumulative hazard function is approximated by a monotone B‐spline function. We extend the generalized Rosen algorithm to compute the maximum likelihood estimate. We show that the estimator of the regression parameter is asymptotically normal and semiparametrically efficient, although the estimator of the baseline cumulative hazard function converges at a rate slower than root‐n. We also develop an easy‐to‐implement method for consistently estimating the standard error of the estimated regression parameter, which facilitates the proposed inference procedure for the Cox model with interval‐censored data. The proposed method is evaluated by simulation studies regarding its finite sample performance and is illustrated using data from a breast cosmesis study.     

略论西北文化的根本特点

西北地区,是指今天地处中国西北部的陕、甘、宁、青、新等五个省区。"西北文化"也就是指这五个地区的文化圈。从整个西北的历史发展和中国西部文化的内在结构来看,西北文化呈现出会聚性、多样性、交融性和多变性的特点。     

广西区域经济增长趋同与分异研究——基于广西14个城市的实证分析

以新古典经济增长的α趋同和β趋同理论为基础,依据1995～2010年广西14个城市的人均GDP,采用回归分析方法,对广西区域经济增长过程中存在的趋同和分异现象进行实证研究。研究发现,在检验期内广西区域整体上存在α趋同和绝对β趋同,在加入人口增长率、工业化水平、外贸依存度和固定资产投资率等控制变量后存在条件β趋同,但在某些时间阶段却存在经济增长的分异。根据广西经济增长的趋同与分异变化规律,提出了促进广西区域经济发展一体化的对策与建议。     

Convergence Properties of the Likelihood of Computed Dynamic Models

This paper studies the econometrics of computed dynamic models. Since these models generally lack a closed‐form solution, their policy functions are approximated by numerical methods. Hence, the researcher can only evaluate an approximated likelihood associated with the approximated policy function rather than the exact likelihood implied by the exact policy function. What are the consequences for inference of the use of approximated likelihoods? First, we find conditions under which, as the approximated policy function converges to the exact policy, the approximated likelihood also converges to the exact likelihood. Second, we show that second order approximation errors in the policy function, which almost always are ignored by researchers, have first order effects on the likelihood function. Third, we discuss convergence of Bayesian and classical estimates. Finally, we propose to use a likelihood ratio test as a diagnostic device for problems derived from the use of approximated likelihoods.     

Retention or omission of the ne in advanced French interlanguage: The variable effect of extralinguistic factors

This article considers inter‐individual variation in omission rates of the preverbal particle ne in 991 negations produced in conversations between 73 native and non‐native speakers of French. It appears that both endogenous and exogenous extralinguistic factors are linked to omission rates of ne . Whereas age and gender were found to have little effect, the degree of extraversion of the speaker, the frequency of use of French and the native/non‐native status of the speakers were correlated with omission rates. Among the exogenous factors it appeared that the composition of the dyad was linked to omission rates: non‐native speakers interacting with native speakers omitted the ne more frequently than the non‐native speakers in conversation with other non‐native speakers. The theoretical implications of these findings are discussed.     

Strong convergence rate of the least median absolute estimator in linear regression models

We propose a least median of absolute (LMA) estimator for a linear regression model, based on minimizing the median absolute deviation of the residuals. Under some regularity conditions on the design points and disturbances, the strong convergence rate of the LMA estimator is established.     

整体论进路与乡土共同体--论"儒法合流"的成立基础

作为中国传统政治文化基本模式的"儒法合流",其成立基础可以从两个方面考察:一是它们共同具有的整体论进路,在儒家是强调"家族本位",并通过"孝"的中介而连接到国家;在法家是赤裸裸的国家本位,其实质是强调君主私利.它们在操作层面的关联是通过儒学的意识形态化来实现的.二是国家与乡土共同体之间的张力,即由于中国社会发展道路的特殊性,在秦汉地域制国家产生以后,乡村社会基于血缘关系的乡土共同体并没有随之消解,国家政权力量还不能在长期内有效延伸到乡村,这些地域的社会整合必须借助儒学的教化作用.     

Modelling Dependence within Joint Tail Regions

Standard approaches for modelling dependence within joint tail regions are based on extreme value methods which assume max-stability, a particular form of joint tail dependence. We develop joint tail models based on a broader class of dependence structure which provides a natural link between max-stable models and weaker forms of dependence including independence and negative association. This approach overcomes many of the problems that are encountered with standard methods and is the basis for a Poisson process representation that generalizes existing bivariate results. We apply the new techniques to simulated and environmental data, and demonstrate the marked advantage that the new approach offers for joint tail extrapolation.