资源环境约束下中国TFP增长的空间差异和影响因素

运用DDF模型和ML生产率指数,对中国分省资源环境约束下的区域全要素生产率进行测算,采用Theil指数测算资源环境约束下中国全要素生产率增长的地区差异并按照多种空间尺度进行区域分解;构建空间面板数据模型,采用广义空间面板自回归最小二乘法对资源环境约束下全要素生产率增长的影响因素进行实证研究。研究结果表明,在2010年之前,资源环境约束下中国全要素生产率增长的空间差异总体上呈下降态势,地区内而非地区间差距是造成总体空间差异的主要来源。空间计量模型回归估计结果表明,资源环境约束下全要素生产率增长存在显著的正向空间溢出效应,经济发展水平、贸易开放和科技创新水平对资源环境约束下全要素生产率增长存在显著的促进作用,产业结构、能源结构和要素禀赋结构等结构因素对全要素生产率增长存在显著的负向影响,外商直接投资和环境规制水平对全要素生产率增长的影响在统计上并不显著。     

基于前沿分析方法的中国工业部门 广义碳生产率指数测算及变化分解

碳生产率能将低碳经济的两大目标融为一体,工业部门作为能源密集型部门,是二氧化碳排放的主体,其碳生产率的变化深刻影响着中国整体碳生产率的格局。目前,大部分学者都用GDP与二氧化碳排放量的比值作为衡量碳生产率的指标,然而二氧化碳排放空间作为一种投入要素,其产出除了经济绩效外还包括环境、就业等综合绩效。本文基于广义碳生产率的概念,通过对前沿分析方法的比较,选择基于方向性距离函数的DEA方法,测算了中国工业部门各细分行业从2004-2009年的广义碳生产率指数,并对其变化进行了分解。结果表明:(1)中国工业部门广义碳生产率指数整体小于1,说明广义碳生产率水平整体上存在下降的趋势;(2)引致工业部门广义碳生产率指数整体小于1的主要原因是技术效率和规模效率低下。     

市场化转型、就业动态与中国地区生产率增长

中国从计划经济体制向市场经济体制转型的渐进式改革已经持续了30多年,特别是进入21世纪之后,中国各地区的市场化进程更是进一步加快。本文以此为背景来评估市场化转型对中国就业动态变化(包括就业创造与就业破坏)以及地区生产率增长的影响。利用1998~2007年中国工业企业数据进行深入的实证研究,本文发现,市场化转型通过"提升就业创造率"和"降低就业破坏率"两个途径显著地促进了中国就业净增长,并且前者的影响更大。本文的另一个重要发现是,市场化转型促进了劳动力资源由低生产率企业向高生产率企业的转移,即通过改善就业再配置效率进而显著地促进地区全要素生产率的增长。上述发现对于深入认识和理解转型国家的就业变动模式与生产率增长的动力来源具有重要的意义。     

生产分割、区域间贸易与CO_2排放:基于IRIO模型的研究北大核心CSSCI

当前,国际生产分割快速发展,传统的生产者责任污染排放核算面临挑战,消费者责任核算受到越来越多的关注。实际上,一国内部地区间的生产分割程度较之国际更高,地区间贸易隐含碳研究却相对较少。数据可得性较差是最重要的原因之一。本文利用半官方的区域间投入产出表,辅以海关数据,调整加工贸易影响;并基于改进的区域间投入产出模型,研究了生产分割下地区间贸易隐含碳排放。进而,提出拓展的"碳排放要素"HOV模型,预测隐含碳的净流向。模型证实,各区域"生产碳排放"与"消费碳排放"之差,等于各区域"隐含碳净流量",生产碳排放可由消费碳排放与隐含碳净流出加总得到。实证结果显示:京津区域、东部沿海区域等经济发达区域的消费碳排放大于生产碳排放,它们是隐含碳净流入地区;而东北区域、西南区域等地区是隐含碳净流出地区,即地区发展中高排放产业转移造成的污染转移多从经济发达地区向欠发达地区转移,表明地区间碳排放转移差异巨大,这增加了碳排放交易的难度和不确定性。2002年和2007年"碳排放要素"HOV模型的预测成功率分别为75%和89%,该结果与以往对于国家层面研究相比,理论与实证相符程度更高,说明一国内部各区域更接近HOV模型的经典假设。对各区域碳排放影响因素的分解结果显示,多数地区的资本形成是消费碳排放的主因,这从侧面反映了我国投资驱动型的经济增长模式。通过对2002年和2007年两个时点的比较发现,各地区的消费碳排放本地市场效应明显,但随着时间在逐步减弱,意味着地区环境政策的有效性需要考虑区际贸易。本文最后提出了相应的政策建议。     

数字交易水平、制造业范式变革对区域全要素碳绩效提升的影响

数字交易模式的井喷助推制造业范式变革，全要素碳绩效提高是产业结构转型下绿色经济发展的使然。基于超效率SBM-DEA模型，测度2013-2019年中国30省市全要素碳绩效，应用面板分位数模型、偏差校正LSDV模型及结构分位数模型等，检验数字交易水平、制造业范式变革对全要素碳绩效的影响机制。研究结果表明：我国全要素碳绩效水平在样本期内总体呈现上升趋势，区域差异性明显；数字交易水平的提高会显著提升全要素碳绩效水平，其驱动效会应随分位点的上升逐渐增强；第二产业增加值占比的上升会削弱数字交易水平对全要素碳绩效的促进效应；当前我国制造业范式变革中存在产业结构合理化和高级化间的不协调因素，制约着数字交易水平对碳绩效提升作用的发挥。因此，要顺应新一轮科技革命和产业变革趋势，提升制造业在二产中的份额，增强制造业的科技化效应，以提升区域全要素碳绩效，实现绿色低碳可持续发展。     

新型城镇化视角下中国碳生产率影响因素研究——基于VEC模型的动态关系分析

运用VEC模型碳生产率增长影响因素进行实证研究,结果显示,短期内经济增长是影响碳生产率的主要因素且促进了碳生产率增长,能源强度和新型城镇化水平则为次要影响因素,而产业结构在长期内有利于碳生产率增长。     

中国生产性服务业发展的影响因素研究

明晰和识别中国各地区生产性服务业发展的影响因素,能为不同区域制定合理的产业政策、有效促进区域经济发展提供依据.在理论分析基础上,利用1997年～2006年中国各地区生产性服务业和经济发展的有关数据,利用面板数据模型考察和识别中国转型时期专业化分工、产权结构、效率、工业结构、工业化进程和制造业集聚对东部、中部和西部生产性服务业发展的影响.结果表明,专业化程度加深、效率提高、非国有产权比重的增加与各地区生产性服务业发展显著正相关,而高新技术产业发展对现阶段生产性服务业发展有抑制作用,工业化进程的推进对各地区生产性服务业发展影响微弱;分工深化对东部地区生产性服务业发展的影响最大,而产权结构改变对中部地区影响最大,分工深化和非国有经济比重提高对西部地区生产性服务业发展均有强有力的促进作用.     

绿色生产率及其对工业低碳发展的影响研究

基于1995年至2009年碳排放特征分组的中国工业投入产出数据,采用方向距离函数估算工业的生产效率和绿色生产率,基于方向距离函数的SML指数方法测算绿色生产率增长指数,从时间和行业两个维度比较分析工业绿色生产率的变化趋势和行业差异,结合改进的STIRPAT模型面板数据模型估计方法,就绿色生产率对工业低碳经济发展的作用及影响工业低碳发展的主要因素进行实证研究.研究结果表明,相对于不考虑碳排放的生产效率,绿色生产率在高碳排放强度行业上升,在低碳排放强度行业下降;绿色生产率先升后降,对工业低碳发展有显著正向影响,对高碳排放强度行业作用更大;绿色技术进步对工业绿色生产率增长和低碳经济发展的促进作用显著大于绿色技术效率;碳排放强度与经济产出关系具有U型曲线特征,化石能源结构调整不能促进工业低碳发展.     

对外直接投资对绿色全要素生产率的空间效应影响

基于2004—2016年中国30个省（市、自治区）的面板数据,通过空间杜宾计量模型（SDM）实证研究了对外直接投资（OFDI）对绿色全要素生产率的空间效应影响。结果显示：各地区绿色全要素生产率及其分解项存在明显的地区差异;绿色全要素生产率、绿色技术进步和绿色效率变化存在显著的空间相关性;OFDI逆向技术溢出能够显著的促进本地区绿色全要素生产率提高,并且存在显著的空间溢出效应;FDI技术溢出对绿色技术进步具有显著的正向推动作用;进口技术溢出和自主研发能够显著促进绿色全要素生产率和绿色技术进步的提升;环境规制强度对我国绿色全要素生产率具有非线性影响。     

碳市场中市场势力对减排技术采用的影响

碳市场是助力中国实现双碳目标和能源转型的重要市场工具。本文研究了当企业处于不完全竞争的产品市场时,碳市场中的市场势力对低碳减排技术采用与扩散的影响。我们将异质性企业刻画引入Reinganum提出的技术采用模型框架,构建了碳交易背景下的异质性企业策略性技术采用博弈模型。模型中企业需要同时考虑采用新减排技术的效益和成本,以及其竞争对手的策略性行为,从而确定采用新技术的最佳时间。理论分析与仿真结果表明,有市场势力的情况下,企业都将推迟采用新的低碳减排技术。而且当产品需求与弹性较小时,它将导致更晚的技术扩散。本文研究结论为碳市场推进低碳减排技术扩散的机制设计和优化提供更多的理论参考依据,有力推动中国绿色低碳转型。     

On Approximation Ratios of Minimum-Energy Multicast Routing in Wireless Networks

In the broadcasting of ad hoc wireless networks, energy conservation is a critical issue. Three heuristic algorithms were proposed in Wieselthier et al.(2001) for finding approximate minimum-energy broadcast routings: MST(minimum spanning tree), SPT(shortest-path tree), and BIP(broadcasting incremental power). Wan et al.(2001) characterized their performance in terms of approximation ratios. This paper points out some mistakes in the result of Wan et al.(2001), and proves that the upper bound of sum of squares of lengths of the edges in Euclidean MST in unit disk can be improved to 10.86, thus improves the approximation ratios of MST and BIP algorithm.Supported by Natural Science Foundation of China (60223004, 603210022)     

环境约束下的中国全要素能源效率测度及其收敛性

基于省际面板数据和meta-frontier方法,利用数据包络分析方法构建非参数前沿,分析比较了2000～2008年中国全要素能源效率的区域差异,采用"技术差距比"衡量中国三大地区之间能源利用的技术差距,并在此基础上运用收敛性分析考察了全国和三大地区全要素能源效率的趋同情况。结果表明:中国全要素能源效率整体水平较低且区域差异显著,存在巨大的节能减排潜力;三大地区生产技术差距明显;共同前沿和区域前沿下的σ检验结果均显示全国和三大地区全要素能源效率不存在收敛趋势,表明中国各省份全要素能源效率的差距有进一步扩大的危险。     

An expanded decomposition of the Luenberger productivity indicator with an application to the Chinese healthcare sector

The objective of this research is to combine productivity analysis at the “firm-level” and the “industry-level” so that a novel, fuller decomposition of the sources of productivity change can be undertaken. Productivity change is decomposed into technological progress, technical, mix, and scale efficiency effects. Specifically, our decomposition allows us to capture changes in productivity due to the reallocation of inputs or outputs across productive units. In practice, such reallocation might take place across plants operated by the same firm, across regions within a country, or via mergers and acquisitions. The new decomposition of the aggregate Luenberger productivity indicator is illustrated using data at both the provincial and regional levels for China's healthcare sector over the period 2009–2014. Our results indicate that the growth of the aggregate Luenberger productivity indicator varied across both time and regions. We find that China's regional productivity growth in healthcare was primarily driven by technological progress, while the contributions of the other components of productivity change were smaller and more varied across regions.     

Critical edges/nodes for the minimum spanning tree problem: complexity and approximation

In this paper, we study the complexity and the approximation of the k most vital edges (nodes) and min edge (node) blocker versions for the minimum spanning tree problem (MST). We show that the k most vital edges MST problem is NP-hard even for complete graphs with weights 0 or 1 and 3-approximable for graphs with weights 0 or 1. We also prove that the k most vital nodes MST problem is not approximable within a factor n ^1?? , for any ?>0, unless NP=ZPP, even for complete graphs of order n with weights 0 or 1. Furthermore, we show that the min edge blocker MST problem is NP-hard even for complete graphs with weights 0 or 1 and that the min node blocker MST problem is NP-hard to approximate within a factor 1.36 even for graphs with weights 0 or 1.     

ILP formulation of the degree-constrained minimum spanning hierarchy problem

Given a connected edge-weighted graph G and a positive integer B, the degree-constrained minimum spanning tree problem (DCMST) consists in finding a minimum cost spanning tree of G such that the degree of each vertex in the tree is less than or equal to B. This problem, which has been extensively studied over the last few decades, has several practical applications, mainly in networks. However, some applications do not especially impose a subgraph as a solution. For this purpose, a more flexible so-called hierarchy structure has been proposed. Hierarchy, which can be seen as a generalization of trees, is defined as a homomorphism of a tree in a graph. In this paper, we discuss the degree-constrained minimum spanning hierarchy (DCMSH) problem which is NP-hard. An integer linear program (ILP) formulation of this new problem is given. Properties of the solution are analysed, which allows us to add valid inequalities to the ILP. To evaluate the difference of cost between trees and hierarchies, the exact solution of DCMST and z problems are compared. It appears that, in sparse random graphs, the average percentage of improvement of the cost varies from 20 to 36% when the maximal authorized degree of vertices B is equal to 2, and from 11 to 31% when B is equal to 3. The improvement increases as the graph size increases.     

中国区域经济差距收敛性的协整检验

本文根据1957-2006年人均实际GDP数据,运用协整检验方法对中国东中西三大地带内和地带间经济增长的收敛性进行了检验,从一个新视角研究了我国的区域经济差距问题。结果发现,我国东部地区内部各省经济差距存在收敛趋势,而中部和西部地区内部的经济差距却不存在收敛趋势,但它们的经济增长在长期都受到三个共同冲击的影响;我国三大经济带之间以及经济带两两之间的经济差距不存在收敛趋势,但三大经济带的经济增长在长期受到两个共同冲击的影响。     

Weighted Inverse Minimum Spanning Tree Problems Under Hamming Distance

In this paper, we consider weighted inverse minimum spanning tree problems under Hamming distance. Three models are considered: unbounded case, unbounded case with forbidden edges, and general bounded case. In terms of the method for minimum-weight node cover problem on bipartite graph, we present their respective strongly polynomial algorithms.This research is supported by TRAPOYT, National Natural Science Foundation of China (10271110, 60021201)     

Effects of Regional Labour Markets on Migration Flows,by Education Level

European economies display large variations in unemployment rates across regions as well as between education groups. Insufficient labour mobility is widely believed to contribute to higher regional disparities and overall unemployment, but few studies have compared mobility responses of different education groups to regional shocks. This paper employs administrative registers covering the entire Norwegian population to compute annual time series from 1994 to 2004 of migration flows and regional labour market conditions by education level for 90 travel‐to‐work areas. We find that regional disparities in unemployment rates are decreasing in education level, whereas the response of migration flows to regional unemployment shocks is increasing in education level. The results suggest that low regional mobility of low‐educated workers may contribute to higher regional disparities and higher overall unemployment among the low educated.     

Regional Disparities and Labour Mobility: the Euro-11 versus the USA

In this paper we assess whether regional disparities in the euro area stimulate labour mobility, using migration behaviour in US states as a benchmark. Large regional disparities within European countries and size differences between them and US states led us to select regions as the appropriate unit of analysis for Europe. While the level of net immigration flows with respect to population is similar in the USA and the euro area, our study shows that its sensitivity to regional disparities differs considerably. Indeed, migration is much more significantly influenced by income disparities in the USA than it is in the Euro-11, both in the short and the long term. Furthermore, the responsiveness of net migration inflows to shocks to the relative unemployment rate is negative in the regions of the USA, but nil in those of the Euro-11. Finally, risk factors (identified in the theoretical model as the variance of income) are significant determinants of migration decisions in Europe but not in the USA.