Efficient Semiparametric Estimation via Moment Restrictions

Conditional moment restrictions can be combined through GMM estimation to construct more efficient semiparametric estimators. This paper is about attainable efficiency for such estimators. We define and use a moment tangent set, the directions of departure from the truth allowed by the moments, to characterize when the semiparametric efficiency bound can be attained. The efficiency condition is that the moment tangent set equals the model tangent set. We apply these results to transformed, censored, and truncated regression models, e.g., finding that the conditional moment restrictions from Powell's (1986) censored regression quantile estimators can be combined to approximate efficiency when the disturbance is independent of regressors.     

多人从经验中学习模型研究：基于信息和分析方法的异质性视角

多人从经验中学习时,常常出现由于不同个体掌握的信息和分析方法不同,而导致的学习效率低的现象。基于时空理论,本文分析了多人从经验中学习时的信息异质性和分析方法异质性,并构建了信息结构异质性和信息内容异质性的桥梁结构,以及分析方法集。本文还对导致信息和分析方法错误的因素和对应的解决方法进行了阐述。进一步地,本文构建了基于信息和分析方法的异质性视角的多人从经验中学习过程机制模型,认为在可用的资源的制约下,多人可以通过“清洗”和“清除”信息和分析方法来提高信息真实性和分析方法可用性,通过“寻找”提高信息和分析方法的完整性,以达到学习目标的具体要求,从而提升学习效率,并列举了一些实践工具。本文从信息和分析方法的异质性视角出发,对多人从经验中学习时可能遇到的问题和解决方法进行探索,为提升学习效率提供理论依据和实践建议。     

论英语词汇学习的记忆、遗忘与效率提高

阐述了外语记忆的理论,分析了外语记忆和遗忘的原因及其规律,其目的在于有针对性地提出一些提高英语词汇学习记忆效率的具体策略。     

高端装备制造业技术创新资源配置效率及影响因素研究——基于两阶段StoNED和Tobit模型的实证分析

新常态下,高端装备制造业在推动国民经济稳定增长、加快传统工业转型升级、提升产业链核心竞争力的过程中,先导性和战略性作用日益凸出,但其技术创新资源配置的合理性和有效性却成为产业持续发展的主要瓶颈。本文从投入产出角度出发,基于价值链理论,将技术创新活动分为技术研发和技术转化两个阶段,并构建两阶段StoNED模型,采用2011-2014年的行业面板数据作为样本数据,对高端装备制造业技术创新资源配置效率进行测度和比较;以产业组织为视角,利用Tobit模型分析影响效率的关键因素。实证研究表明,我国高端装备制造业技术创新资源配置的整体和阶段效率在子行业间存在不同程度的波动和差异,技术研发阶段效率偏低制约着整体效率的最优化;甄别影响因素发现,企业规模对技术研发阶段效率具有负向作用,对整体和技术转化阶段效率具有正向作用;市场垄断不利于整体和技术转化阶段效率的提升;政府支持对整体和两阶段效率均具有负面影响。在此基础上,进一步提出应对产业技术创新资源配置现状的对策建议。     

论系列合同中的第三人权利

系列合同是围绕着一个中心事件而在不同当事人之间缔结多份合同的现象。按合同相对性原则,合同效力不及于第三人,因此第三人不能针对违约当事人请求救济。然而出于社会正义和司法效率的考量,在系列合同中,赋予受损害的第三人以合同上权利,直接寻求针对违约当事人的权利救济是有正当理由的。实践中,系列合同呈现辐射式和链式两种不同的形态,第三人在不同形态的系列合同中获得救济的条件和方式也有所差异。     

中国玉米生产技术效率分析：2001～2008——基于随机前沿生产函数

利用2001-2008年中国22个玉米主产区的投入与产出面板数据建立了随机前沿生产函数模型,并对中国玉米生产的技术效率进行了测算,全国玉米生产平均技术效率为0.862。在此基础上,进一步探讨分析了技术效率的时间差异、地区差异和收敛性,发现玉米生产技术效率随时间波动且地区差异明显,但从全国来看,各省份之间的玉米生产技术效率的差距正在逐步缩小,具有趋同的趋势。今后应提高玉米生产技术效率,加大政府投入力度,提高机械化水平,进行科学管理;加强玉米生产技术的研发和创新。     

Public sector efficiency in the design of a euro-area social benefit scheme

This study examines the importance of public sector efficiency in the design of a euro area-wide social benefit scheme. Our results reveal large-scale inefficiencies in the use of funds allocated to the scheme during the great recession and euro area sovereign debt crisis that followed, with member states wasting on average 34.6% of funds allocated to it. We therefore propose that to ensure the smooth functioning of the scheme, the fiscal union will first of all have to strengthen it at the national level by improving efficiency in the use of funds by governments. We show that this can be achieved by providing a framework for the transfer of the “critical success factors” in the policies implemented by the most efficient administrations. Furthermore, we show how public sector efficiency considerations can help ameliorate the problem of moral hazard associated with a centralized insurance scheme.     

Comparison of efficiencies of some symmetry tests around an unknown centre

In this paper, some recent and classical tests of symmetry are modified for the case of an unknown centre. The unknown centre is estimated with its α-trimmed mean estimator. The asymptotic behaviour of the new tests is explored. The local approximate Bahadur efficiency is used to compare the tests to each other as well as to some other tests.     

Locally efficient semiparametric estimators for a class of Poisson models with measurement error

The presence of measurement error may cause bias in parameter estimation and can lead to incorrect conclusions in data analyses. Despite a large body of literature on general measurement error problems, relatively few works exist to handle Poisson models. In this article we thoroughly study Poisson models with errors in covariates and propose consistent and locally efficient semiparametric estimators. We assess the finite sample performance of the estimators through extensive simulation studies and illustrate the proposed methodologies by analyzing data from the Stroke Recovery in Underserved Populations Study. The Canadian Journal of Statistics 47: 157–181; 2019 © 2019 Statistical Society of Canada     

基于DEA交叉评价的中部六省服务业效率

通过建立服务业效率的DEA交叉评价模型,对中部六省2009年传统服务业与新兴服务业效率的测度和进一步分解的实证结果表明：DEA交叉评价能够克服传统DEA模型的缺陷,得到合理的排序结果;新兴服务业是六省竞争的关键,同时应推动传统服务业改造,不断提升效率水平。