Agricultural Total Factor Productivity and Income Gap between Urban and Rural Residents--An Empirical Study Based on Provincial Panel Data

Taking the relevant data of 27 provinces in China during 2013 and 2017 as samples,this paper firstly measured the agricultural total factor productivity( TFP) using Malmquist index method. Then,it built the panel data model,and empirically tested the impacts of agricultural TFP on the income gap between urban and rural residents. The results show that the improvement in agricultural TFP can promote the narrowing of the income gap between urban and rural residents,and the factors such as urbanization level and industrial structure also have significant impacts on the income gap between urban and rural residents. On the basis of these,it came up with recommendations,including increasing agricultural human capital investment and establishing agricultural production research institutions.

新疆南北疆区域经济差异的影响因素——基于Panel数据的实证研究

区域经济差异是多种因素综合作用的结果。以新疆维吾尔自治区1997—2009年的面板数据为基础,对新疆南北区域经济发展的影响因素进行了实证分析。研究结果表明,政策因素、工业化程度、人力资本和投资因素对新疆区域经济差异的形成均具有显著的影响,但这些因素对新疆南疆地区和北疆地区具有不同的影响方式和影响作用,其中财政收入和全社会固定资产投资对南疆地区经济增长的拉动作用较大,而工业生产总值、外贸进出口总额和劳动力数量对北疆地区经济增长作用明显。基于此,本文提出了缩小新疆南北疆区域经济差异的政策建议。

基于Panel-data的区际产业转移粘性分析

利用面板数据模型,以江苏省为例,对28个制造业的科技进步、产业集群、区域人力资本积累、沉没成本和资产专用性、劳动力跨区域流动、制度创新、政府阻力等因素对产业转移粘性的关系进行了实证研究,并依据各个因素的贡献率得出了跨区域产业转移的初步结论。

基于Panel Data模型的内蒙古房地产价格影响因素的区域性差异研究

以地方GDP、地方财政收入、职工平均工资、房地产开发投资额为影响内蒙古房地产价格的主要指标,选取2001—2014年内蒙古12个盟市的相关数据,运用面板数据模型,将12个盟市分为中、东、西三个区域,并对影响三个区域房地产价格的因素进行差异性分析。结果表明,内蒙古房地产价格的影响因素确实存在明显的区域差异。地方GDP对房地产价格的影响在西部最强,中部次之,东部不显著;财政收入和房地产开发投资额对房地产价格的影响程度并不大,明显小于另外两个变量;职工平均工资对中、东、西部的影响东部最大,中部次之,西部不显著。

基于Panel-data的江苏省区域经济增长要素分析

利用江苏省2002—2010年的面板数据,研究资本要素、制度因素、消费结构对江苏省区域经济增长的影响。研究表明:资本和外贸依存度对经济增长的贡献显著,对3大区域的经济增长都起到积极促进的作用;农村恩格尔系数对于苏中地区的贡献是显著的,说明提高苏中地区农村的消费水平有助于促进苏中经济的增长。

基于Panel Data模型的住宅价格影响因素研究——以河北省为例

文章引入Panel Data模型,结合河北省住宅市场相关数据,建立住宅价格影响因素模型,通过实证分析找出了影响河北省住宅价格的主要因素。在此基础之上,结合河北省住宅市场的具体情况,提出了调控河北省住宅价格的措施和建议。

Residual Strength of Stiffened LY12CZ Aluminum Alloy Panels with Widespread Fatigue Damage

Experimental and analytical investigations on the residual strength of the stiffened LY12CZ aluminum alloy panels with widespread fatigue damage （WFD） are conducted. Nine stiffened LY12CZ aluminum alloy panels with three different types of damage are tested for residual strength. Each specimen is pre-cracked at rivet holes by saw cuts and subjected to a monotonically increasing tensile load until failure is occurred and the failure load is recorded. The stress intensity factors at the tips of the lead crack and the adjacent WFD cracks of the stiffened aluminum alloy panels are calculated by compounding approach and finite element method （FEM） respectively. The residual strength of the stiffened panels with WFD is evaluated by the engineering method with plastic zone linkup criterion and the FEM with apparent fracture toughness criterion respectively. The predicted residual strength agrees well with the experiment results. It indicates that in engineering practice these methods can be used for residual strength evaluation with the acceptable accuracy. It can be seen from this research that WFD can significantly reduce the residual strength and the critical crack length of the stiffened panels with WFD. The effect of WFD crack length on residual strength is also studied.

基于Panel Data模型的生产者服务业区域发展影响因素

利用面板数据误差修正模型考察了制造业规模、投资、就业、区域经济水平、城市化水平等因素对我国东部、中部和西部的生产者服务业发展的长期和短期影响.结果发现,除了区域经济水平在长期和短期都对本区域生产者服务业具有显著的促进作用以外,其他影响因素在不同区域的影响方向和大小有所不同.从长期来看,东部地区制造业规模对生产者服务业具有挤出效应,而投资和就业能显著地促进行业发展;中部地区投资、就业和城市化水平都对生产者服务业产生了负向影响;西部地区除了制造业规模影响为负值之外,其他因素都能促进行业发展.从短期来看,东部除了投资、中部和西部除了城市化之外,其他因素基本上对行业发展具有正效应.

粮食主产区农民收入增长要素的Panel Data模型分析

运用Panel Data模型对中国粮食主产区农民收入增长要素进行了计量分析,结果表明,农业生产条件、农业生产资料的使用、农产品价格水平、农业生产结构、资本投入等因素对粮食主产区农民人均农业纯收入增长具有显著影响.

基于Panel Data的山地城市立交基本段通行能力影响因素研究

通过统计学分析,基于重庆市主城区不同立交基本段采集的交通流与道路线型等数据,建立Panel Data(面板数据)模型,研究山地城市立交基本段通行能力的主要影响因素,确定通行能力与主要影响因素间的数学关系,对主要影响因素的敏感度排序.结果表明:竖曲线半径、设计速度、圆曲线半径、大车比例是影响山地城市立交基本段通行能力的主要因素,其中,竖曲线半径对通行能力的影响最大,敏感度最高,为20.66%;道路坡度由于影响权重较小,被大车比例取代.

Experimental Study of Environmental Impact on the Efficiency of a House-Hold PV Panel

House-hold PV panels are widely used;however, their performance is significantly degraded under real operating conditions. Environmental factors such as ambient temperature, wind speed, and solar irradiance has a major impact on the house-hold PV panel efficiency. In this paper an experimental study was conducted during the winter period in a single building in Minqin county, Gansu province, China. The experimental measurements were used to quantify the house-hold PV panel performance and operating characteristics. Based on the experimental results the house-hold PV panel performance is basically affected by the PV surface temperature, therefore, multilevel of energy is detected. Approximately 3% efficiency variation is detected due to the impact of the environmental factors.

Effect of Facet Displacement on Radiation Field and Its Application for Panel Adjustment of Large Reflector Antenna

Large reflector antennas are widely used in radars, satellite communication, radio astronomy, and so on. The rapid developments in these fields have created demands for development of better performance and higher surface accuracy. However, low accuracy and low effi- ciency are the common disadvantages for traditional panel alignment and adjustment. In order to improve the surface accuracy of large reflector antenna, a new method is pre- sented to determinate panel adjustment values from far field pattern. Based on the method of Physical Optics （PO）, the effect of panel facet displacement on radiation field value is derived. Then the linear system is constructed between panel adjustment vector and far field pattern. Using the method of Singular Value Decomposition （SVD）, the adjustment value for all panel adjustors are obtained by solving the linear equations. An experiment is conducted on a 3.7 m reflector antenna with 12 segmented panels. The results of simulation and test are similar, which shows that the presented method is feasible. Moreover, thediscussion about validation shows that the method can be used for many cases of reflector shape. The proposed research provides the instruction to adjust surface panels efficiently and accurately.

Linear Panel Data and Farming Cash Flow Analyses to Assess the Causes of Deforestation in the Upper Guinean Forest: Data and Evidence from the Prefectures of the Central Region in Togo

We present a careful quantitative description of land use in central Togo, by constructing farm budgets and analyzing time series data on agricultural production in four prefectures over the time period from 1996 to 2015. One key finding is that higher prices for chemical inputs are associated with more deforestation (as proxied by area in yam production), and correspondingly, greater quantities of chemical inputs applied are associated with less deforestation. This confirms that chemical fertilizers and forest clearing are substitutes and suggests that one path to reducing deforestation is to increase agricultural productivity, and to provide farmer with agricultural risk assistance that covers the farming negative externality costs. This risk assistance may include the coverage for the environmental deterioration costs, and the subsidies to compensate for investments’ cost.

数字普惠金融赋能乡村振兴的效率及影响因素——基于30个省(市、自治区)的面板数据

采用2011—2020年北京大学数字普惠金融指数,运用熵值法测算乡村振兴指数,基于DEA模型计算数字普惠金融赋能乡村振兴的效率,并采用Tobit模型分析效率的影响因素。结果表明,中国数字普惠金融赋能乡村振兴综合效率的水平较低,存在地区差异,数字普惠金融赋能乡村振兴的发展空间仍然较大;技术进步变动是影响效率变动的主要原因;在影响因素方面,金融中介效率、金融发展规模、产业结构、经济发展水平、财政支农力度与对外开放度对数字普惠金融赋能乡村振兴效率具有显著的正向影响,而信息化基础设施、交通运输水平、经济集聚度对数字普惠金融赋能乡村振兴效率的影响不显著。提出扩大金融发展规模与积极提高金融中介效率;支持产业结构转型升级,扩大对外开放水平,积极培育新的经济增长点;加大财政支农力度,促进数字普惠金融服务三农,提高数字普惠金融赋能乡村振兴的效率。

中国地区性数字鸿沟社会经济成因与治理研究

从互联网发展地区差距出发,结合“普及率”和“基础资源”两个维度,针对21世纪以来中国内地31个省市自治区,以动态面板模型系统GMM方法,进行经济增长、人口统计、居民收入、基础设施、政府干预、对外开放、科技和城镇化发展水平等一系列基本社会经济因素影响分析,并进行各因素影响的相对重要性分析和稳健性检验。结果表明,居民收入与经济增长等因素,对现阶段国内地区性数字鸿沟的形成与演化的确有显著影响;同时,还发现现阶段中国地区性数字鸿沟演化发展的循环累积特性、不同类别因素影响程度的差异,以及不同区域间和不同发展阶段上互联网发展水平受社会经济因素影响的显著差异性。消弭地区性数字鸿沟的关键,主要在于加快基础设施建设、保护弱势群体和深化互联网治理等三个方面。

Effect of Core Thickness and Core Density on Low Velocity Impact Behavior of Sandwich Panels with PU Foam Core

Composite sandwich structures are highly proven materials that provide high strength to weight ratio. However research works are still being carried out in the area of impact characteristics of sandwich composites. This paper provides a better understanding on the effect of core density and core thickness of sandwich panels subject to low velocity drop test. Specific energy absorption capacity of sandwich panels is obtained and factors affecting the same are explored with facings made of woven glass fiber laminates and polyurethane foam core with three different densities of 70 Kg/m3, 100 Kg/m3, 200 Kg/m3.

基于测量误差面板数据的两步分位回归估计方法

该文考虑了含测量误差面板数据模型的参数估计问题.首先通过因子得分法消除自变量中测量误差的影响,获得固定效应面板模型的自变量修正值;随后分别采用一阶差分分位回归法和固定效应分位回归法求得估计量,结合Bootstrap算法得到估计置信区间.蒙特卡罗模拟结果显示,新提出的两步分位回归估计方法在同方差、异方差两种固定效应面板模型下的相对偏差和均方误差均优于传统分位数回归法.最后,基于美国各州实际香烟销售面板数据的实证分析表明,该方法在消除测量误差及提高估计准确性等统计应用分析上具有一定优势,可以为解决实际的复杂动态问题提供可靠依据.

区域创新发展能力评价与空间差异测度

区域创新发展能力是区域经济在发展过程中获取竞争优势的重要影响因素,文章从区域创新发展规模、区域创新发展条件、区域创新发展活力、区域创新发展环境四个子系统筛选出20个可观测指标构建区域创新发展能力评价指标体系,应用面板数据熵权法对我国31个省份2014—2019年创新发展能力进行综合评价,利用泰尔指数和莫兰指数对创新发展能力空间差异特征进行分析,并为区域创新发展能力实现协同发展提供参考。

广东省高等教育规模扩张进程演进及影响因素研究

高等教育作为人才培养的重要渠道,对区域经济发展具有重要影响。该文构建中国情境下高等教育规模扩张机制的理论研究框架。基于广东省21个地级市的面板数据集,运用空间自相关分析、动态空间计量模型,系统揭示广东省高等教育规模的时间演变进程、空间分异特征及影响因素。

环境规制与中国经济绿色增长研究——基于省级面板数据的经验分析

选取2003—2019年中国30个省份的面板数据,基于DEA-Malmquist指数模型测算绿色全要素生产率并分析其时空演变特征。运用动态面板模型和系统广义矩法检验环境规制对中国绿色全要素生产率的影响。研究表明:总体上,环境规制与绿色全要素生产率符合U型关系;分区域来看,东部地区的环境规制与绿色全要素生产率的关系为U型,中部和西部地区为倒U型;从作用机制来看,技术创新在环境规制对绿色全要素生产率的影响过程中发挥正向中介效应。因此,政府应采取分阶段制定环境政策,尽早跨越“波特拐点”;实行差异化规制手段,统筹区域协调发展;加强技术创新,实现绿色经济高质量发展等措施。