Technical Change and Productive Efficiency: Irrigated Rice in the Philippines*

Panel data are used to study the technical efficiency of rice producers in the Philippines. Production efficiency over time is measured using a stochastic frontier regression with error decomposition. Sources of inefficiency are identified and the link between irrigation and productive efficiency is measured. Results suggest that irrigation was associated with higher levels of technical efficiency in the sample.     

随机生产前沿方法的发展及其在中国的应用

本文对随机前沿生产函数模型的发展及其在中国生产率分析中的应用进行了评述。文章首先介绍随机前沿方法的基本原理、估计方法和在面板数据下对全要素生产率增长的分解,随后评述随机前沿生产函数模型的最新进展和在经验分析中的优势与作用,最后总结了在中国行业和地区经济增长研究中随机前沿方法的成果和不足,并探讨今后研究的发展方向。     

A spatial autoregressive stochastic frontier model for panel data incorporating a model of technical inefficiency

By integrating Battese and Coelli’s (1995) model and the spatial autoregressive model (SAR), a spatial autoregressive stochastic frontier model for panel data is developed. The main feature of this frontier model is a spatial lag term of explained variables and the joint structure of a production possibility frontier with a model of technical inefficiency. The model addresses both spatial dependence and heteroskedastic technical inefficiency. This study applies maximum likelihood methods considering the endogenous spatial lag term. The proposed model nests several existing models. Further, an empirical analysis using data on the Japanese manufacturing industry is conducted and the existing models are tested against the proposed model, which is found to be statistically supported. The findings suggest that estimates in the existing spatial and non-spatial models may exhibit bias because of lack of determinants of technical inefficiency, as well as a spatial lag. This bias also affects the technical efficiency score and its ranking.     

薇拉·凯瑟笔下的边疆生活

薇拉·凯瑟描写美国中西部边疆地区的生活的特点：边疆生活是一种野蛮与文明的汇合,以拓荒女为时代的主角,在拓荒的过程中达到了人与自然的和谐共生,实现了田园诗般的生活。     

Labor productivity and migration in Chinese agriculture A stochastic frontier approach

The authors use a stochastic frontier approach with an endogenous error specification to measure China's agricultural labor requirement. They measure a significant apparent labor surplus, but find that it is correlated with factors that affect the incentives of farmers to leave the land. Thus their findings support the hypothesis that declines in the agricultural labor force are not adequately measured, whereas their surplus estimates are generally consistent with other studies using other approaches. The measured surplus ranges from 35% to 40% of the labor force, with significant differences by region. By 1995, there were perhaps 120 million farmers who were either in fact or potentially better employed elsewhere.     

国防重大前沿技术遴选预测方法构建与验证

国防重大前沿技术对于国防科技创新发展和武器装备更新换代具有极为重要的意义.主要军事强国都高度重视国防前沿技术遴选预测研究,制定并发布了大量的战略性规划文件与智库研究报告,开展国防重大前沿技术超前布局和谋划.该文通过系统梳理国外战略文件、智库报告等成果,总结国外国防重大前沿技术预测方法,提出了国防重大前沿技术指标评价体系,有效识别遴选出国防重大前沿技术,为政府与军队相关部门宏观把握国防前沿技术发展方向、开展国防科技战略决策、指导装备体系构建等提供了参考和借鉴.     

Gender earnings differentials in Taiwan: A stochastic frontier approach

We examine Taiwan's male–female earnings gaps over the past three decades in order to assess the progress in assimilating women into the labor market. Two alternative methods of evaluating earnings gaps are employed in this paper: the traditional Oaxaca–Blinder decomposition method and the less well-known method of evaluating labor market efficiency. Men and women's earnings are converging during this period (1978–2003) while at the same time there is little change in the level of gender discrimination measured by the standard Oaxaca–Blinder method. Using the labor market efficiency (stochastic frontier) model we find increases in labor market efficiency over time for both males and females; however, females enjoy a much faster rate of increase in efficiency. We conclude that the relative increase in female efficiency represents a decline in discrimination against females.     

TECHNICAL EFFICIENCY AND PRODUCTIVITY POTENTIAL OF COCOA FARMERS IN WEST AFRICAN COUNTRIES

This paper uses survey data to examine the technical efficiency and productivity potential of cocoa farmers in West and Central Africa. Separate stochastic frontier models are estimated for farmers in Cameroon, Ghana, Nigeria, and Côte d’Ivoire, along with a stochastic metaproduction frontier to obtain alternative estimates for the technical efficiencies of farmers in the different countries. The mean productivity potential of cocoa farmers is also estimated, by using a decomposition result applied to both the national and the metaproduction frontiers. The determinants of technical efficiency are assessed to identify the reasons for differences across countries.     

中国粮食生产的技术效率与全要素生产率增长：1978-2008

本文利用1978—2008年间我国30个省市区的面板数据,对改革开放以来我国粮食生产进行了随机前沿分析。以此为基础,对我国粮食生产技术效率进行了影响因素分析,并对粮食生产全要素生产率增长进行分解和趋势分析。结果表明,农业基础设施建设和制度因素是影响我国粮食生产技术效率的关键因素;我国粮食产量增长主要是由投入要素的增长拉动,31年间全要素生产率的平均增长率为1．17％,TFP对我国粮食产量的贡献很小,其原因在于技术进步与技术效率变化呈现相反趋势。2004年以来,技术效率提高的速度持续下降,技术进步逐渐成为TFP增长的主要动力。     

Asset Market and Balance of Payments Characteristics: An Eclectic Exchange Rate Model for the Dollar,Mark and Yen

In this paper we use an exchange rate model, which combines asset market characteristics with balance of payments interactions, to examine the nominal effective exchange rates of the German mark, Japanese yen and US dollar for the recent experience with floating exchange rates. Our approach may be interpreted as one which attempts to flesh out the missing links that arise in conditioning an exchange rate solely on relative prices, as occurs in a standard PPP analysis. Amongst the results reported in this paper are: significant, and sensible, long-run relationships for the currencies studied; complex short-run dynamics; a variance decomposition analysis which apportions nominal exchange rate error variances into real and nominal elements.     

基于科学知识图谱的冷链物流研究热点及前沿演进

近年来，冷链物流受到国内外学者的高度关注，关于这方面的研究文献与日俱增，但少有文献对冷链物流的研究基础、热点和趋势进行综合研判。因此，通过筛选出WOS数据库和CNKI数据库中从1990—2020年的相关文献，借助CiteSpace可视化分析工具，分析冷链物流研究的演进变化、热点核心和前沿动向。研究表明：中外冷链物流研究整体呈现上升趋势，国内研究起步要晚于国外，但发展速度极快；通过关键词共现分析，整合出“冷链物流、供应链体系、食品冷链、冷链技术”四大冷链物流研究主题；通过突现词分析国内外研究的前沿方向，发现国外研究关注冷链各环节的技术提升，国内则重视食品安全问题与冷链路径优化；最后，中外冷链物流的前沿方向不同，中国侧重于生鲜农产品、遗传算法、路径优化等，国外则侧重于冷链、温度和模型。     

论我国边境安全战略的特点

边境安全战略是维护我国边境安全的总战略，它是在综合分析我国边境安全环境以及边境地区现实情况的基础上制定的，同时也是符合我国的国情的。我国边境安全战略的特点是：以新型安全观为指导思想；以维护边境地区的综合安全为最终目的；以睦邻合作为维护边境安全的主要方式；以外交途径促进边境安全战略的顺利实施。     

EMD联合小波阈值降噪在井下接收信号上的应用

井下闭环旋转导向钻井系统在钻进过程中受到复杂的振动,使井下通信接收装置接收到的信号包含大量的抖动噪声,影响有用信号的提取,从而导致井眼轨迹控制的稳定性变差。为有效降低背景噪声的影响,提高钻井效率,在传统小波变换理论的基础上,结合经验模态分解法(EMD),提出一种 EMD联合小波阈值降噪滤波算法。通过EMD分解法将井下接收信号进行分解,并利用小波变换对高频固有模态函数（IMF）进行降噪处理。仿真结果表明此方法的降噪性能均优于传统降噪算法,实测数据滤波结果显示该方法复原误差较小、信号损失较小、信噪比较高,可有效滤除井下接收信号中的噪声,保证井下接收信号的正确解码。     

湖北县域经济空间差异及影响因素的实证分析

以湖北省80个县域地区为研究对象,将其划分为三个类别。运用泰尔指数与基尼系数方法,结合ArcGIS软件,从空间分解和产业分解两个角度对湖北省县域地区经济发展差异程度进行了测度,并分析了造成经济差异的影响因素。结果显示:2009年—2016年湖北省县域经济发展差异程度逐渐扩大。从空间分解来看,区域内差异是造成差距的主要因素;从产业分解来看,第二产业是造成差距的主要因素。从产业分解另一方面来看,产业结构效应与产业集中效应对经济差异程度影响较大。     

宁波港港口吞吐量对宁波经济影响的实证分析

本文采用1978-2009年的数据,建立计量模型,主要运用时间序列方法中的平稳性检验和协整分析,并在此基础上建立向量误差修正模型和方差分解技术,对宁波港港口吞吐量与宁波经济之间的关系进行实证研究,以期得出促进宁波经济发展的相关政策建议。     

A disaggregated analysis of employment growth fluctuations in Canada

This paper studies the sources of fluctuations in Canadian employment growth disaggregated by province and, within each province, by one-digit industry. Using an error components decomposition, industry-specific shocks are found to be relatively more important in explaining fluctuations in employment growth. Aggregate and province-specific shocks also play an important role, with the latter contributing about 30 percent of the explained variance in employment growth. Using a set of additional identifying assumptions, the decomposition technique is then extended to construct time series on the underlying shocks and to examine their properties.The views expressed in this paper are those of the authors and do not necessarily reflect the views of the International Monetary Fund. The authors are grateful to an anonymous referee for helpful comments.     

基于生产可能性边界的产能过剩行业企业转型升级路径研究

本文基于现阶段产能过剩行业企业在一定时期内资源、技术既定的特点,借鉴宏观经济学中生产可能性边界的分析思路,对产能过剩行业企业的转型升级过程进行研究。分析认为企业转型升级实际上是将转型活动和原生产活动进行利益优化组合和资源配置的过程,其过程应遵循利益相容的原则。对企业而言,建立在上述基础上的转型升级路径更具可行性。     

论中国边境旅游发展的战略意义

以边境口岸互市点为中心开展边境旅游活动。文章以边境旅游产业带动发展理论,分析边境旅游发展的战略意义。     

脚手架中人为错误发生规律的数学模型及其在人因可靠度分析中的应用

人为错误是脚手架坍塌的主要因素.分析此类人为错误的特点,将其分为结构性错误和参数性错误两类,给出基于现场调查数据的初始人为错误发生率的计算方法和错误大小的概率模型,提出改进的证据融合方法,给出错误保有率的区间模型及其计算公式,建立扣件式脚手架中人为错误的数学模型.基于上述数学模型,给出人因可靠度的区间分析方法,为研究脚手架的安全性提供理论基础.     

广西——越南边境旅游发展策略研究

广西—越南边境旅游具有旅游资源类型丰富、边贸发展基础良好、地理区住接壤便利、恰逢东盟博览会和环北部湾经济圈积极发展的时机等优势。为更好地发展广西-越南边境旅游,应拓展广西-越南边境旅游线路范围;凸显广西——越南边境、文化两大特色;强化口岸旅游购物特征;构筑边境旅游休闲度假地;重视第三国游客市场等。