农业保险发展与中国农业全要素生产率增长研究

农业全要素生产率的增长,对于中国全要素生产率的提高、农民收入的增加和粮食安全的保证都具有重要意义。农业生产和农民收益面临着自然风险,农业保险相关政策的实施有助于分散和转移风险,从而影响农户全要素生产率的增长。基于2003—2017年农业农村部全国农村固定观察点数据库的数据,使用动态面板估计和工具变量方法,分析了农业保险覆盖率对农户全要素生产率的影响,并探究了其背后的影响机制。结果表明,中国农业保险覆盖率的提高促进了农户全要素生产率的增长;在中西部地区以及农户为非乡村干部、非少数民族、低收入群组时,农业保险对农户全要素生产率的促进作用更为显著。提高农业保险覆盖率还可以通过增加农户的农药投资、机械投入、耕地规模以及促进农户采用新技术的方式来实现,从而提高农户全要素生产率。

     

体制创新在研究型大学科技创新系统中的功能及其实现机制分析——关于电子科技大学科技发展之路的思考

本文基于对电子科技大学的体制、机制创新的理念、思路、措施及效果的分析,揭示了通过体制创新、促进科技创新、走规模水平并重的特色是高校科技发展的必由之路。     

多变量反馈系统的BIBO稳定化

研究了多变量反馈控制系统的ＢＩＢＯ稳定化问题，对于每一个子系统应用稳定化的局部状态反馈，利用Ｌｙａｐｕｎｏｖ函数和结合矩阵Ｒｌｃｃａｔｉ方程，导出了保证多变量反馈控制系统ＢＩＢＯ稳定化的条件。所获得的这些条件有所改进，并推广了文献［６］的主要结果。     

Central bank credibility and monetary policy in Indonesia

This paper examines the role of central bank credibility in achieving an inflation target and proposes monetary policy rules for Indonesia. Towards that end, we construct and estimate a forward-looking small scale macroeconomic model (SSMM) of the Indonesian economy by adapting the theoretical underpinnings of the well-known Batini–Haldane model, along with the Taylor policy rule. Our results indicate that it is crucial for the Indonesian central bank to bolster its credibility in order to achieve a lower inflation rate. The inflation–output volatility trade-off frontier we derived from the SSMM shows that a monetary policy rule that targets both inflation and output gaps will result in less macroeconomic volatility. We also found that the inclusion of the exchange rate into the rule as an additional feedback variable warrants consideration in the future course of monetary policy management.     

De l'unicité des estimateurs robustes en régression lorsque le paramètre d'échelle et le paramètre de la régression sont estimés simultanément

Several methods have been suggested to calculate robust M- and G-M -estimators of the regression parameter β and of the error scale parameter σ in a linear model. This paper shows that, for some data sets well known in robust statistics, the nonlinear systems of equations for the simultaneous estimation of β, with an M-estimate with a redescending ψ-function, and σ, with the residual median absolute deviation (MAD), have many solutions. This multiplicity is not caused by the possible lack of uniqueness, for redescending ψ-functions, of the solutions of the system defining β with known σ; rather, the simultaneous estimation of β and σ together creates the problem. A way to avoid these multiple solutions is to proceed in two steps. First take σ as the median absolute deviation of the residuals for a uniquely defined robust M-estimate such as Huber's Proposal 2 or the L₁-estimate. Then solve the nonlinear system for the M-estimate with σ equal to the value obtained at the first step to get the estimate of β. Analytical conditions for the uniqueness of M and G-M-estimates are also given.     

我国职业技术教育发展的若干趋势

根据我国经济社会现实状况、发展前景和发达国家职业技术教育运行轨迹,对中国职业技术教育发展趋势作出推断。认为今后较长一段时期,我国职业技术教育总体规模将稳步增长,专业结构将做重大调整,办学形式呈多元化发展趋势,普职融通、教育内容综合化成为必然,培养层次逐渐上移,教育理念由终结性教育转向终身教育。     

关于我国利用外资政策的冷思考

对于广大发展中国家而言,寻求经济的快速发展,积极有效地利用外资是必要的。但是,外资是一把"双刃剑",并非越多越好,这涉及到利用外资的适度规模问题,而外资的规模在很大程度上又是由政府的外资政策所决定的。因此,掌握适度规模的外资以期得出适度的外资政策显得非常有意义。     

Identifiability of Finite Mixtures of Elliptical Distributions

Abstract.  We present general results on the identifiability of finite mixtures of elliptical distributions under conditions on the characteristic generators or density generators. Examples include the multivariate t -distribution, symmetric stable laws, exponential power and Kotz distributions. In each case, the shape parameter is allowed to vary in the mixture, in addition to the location vector and the scatter matrix. Furthermore, we discuss the identifiability of finite mixtures of elliptical densities with generators that correspond to scale mixtures of normal distributions.     

基于网络经济的高技术虚拟企业规模经济分析

实行垂直一体化和多元化经营的大企业可以实现古典和新古典经济学所描述的具有成本优势的规模经济。现代网络经济要求规模经济不仅要具有成本优势,还应具有速度和产品差异上的优势。由一些高科技中小企业各自贡献其核心能力而形成的高技术虚拟企业,可以满足现代市场的新要求,形成了具有速度性和产品差异化优势的规模经济。     

中外人工用材林规模化经营比较研究

本文通过对国内外人工用材林经营方式进行分析，寻找我国人工用材林经营方式的不 足，进而提出通过林工贸一体化实现产业间的协同效应，实现人工用材林由分户经营向规模 化经营的转变，将成为我国人工用材林经营方式的发展趋势。同时文章在对林工贸一体化 实现规模化 经营内在机理进行论述的基础上，提出林工贸一体 化经营是我国人工用材林规模化经营的实现途径。