中国能源强度变动与能源结构、产业结构的动态效应分析

能源强度主要反映一个国家经济结构、能源组合情况以及技术水平.产业结构可以在一定程度上体现国家经济结构,能源组合情况可以由能源结构来表示,能源结构和产业结构是影响能源强度变动的重要因素.文章采用结构向量自回归模型(Structural Vector Autoregression,SVAR),分析1990-2010年能源强度和能源结构、产业结构数据.基于SVAR模型构建的所需条件,对3组变量的时间序列进行平稳性检验与协整检验.检验通过后构建SVAR模型.通过SVAR模型中的脉冲响应函数,分析能源结构与产业结构对能源强度的冲击效应;应用方差分解技术,探究能源结构与产业结构在能源强度变化中的贡献度.结果表明:能源结构对能源强度的冲击效应较小;能源强度受到产业结构的冲击效应较大.并据此给出了相应的政策建议:为了降低能源强度,需要优化产业结构,降低煤炭在能源结构中的消费比重,提高能源效率.     

中国交易费用变动的动态机制和传导路径——一个基于VAR方法的实证研究

为了拓展交易费用定量研究的领域,有必要对我国体制转型时期交易费用变动的动态机制和传导路径进行实证分析。根据研究目的和数据特征,借助基于向量自回归(VAR)模型的脉冲响应函数和方差分解方法,可以具体测算交易费用对经济增长变动和对体制转型程度的变动的敏感程度,进而比较二者对交易费用变动的贡献率大小。     

我国货币政策外部时滞的实证分析

本文运用向量自回归的脉冲响应函数和方差分解分析了货币政策的中介变量对目标变量的时滞效应。其中中介变量选取的是货币供应量与信贷规模,目标变量是居民消费物价水平,根据2000年1月到2011年1月的数据做实证检验,结果表明货币供应量对居民消费物价水平的作用时滞在2-3个月左右,金融机构的信贷规模对居民消费物价水平的作用时滞在4个月左右。     

技术进步对全要素能源效率的空间溢出效应及其分解

本文利用中国大陆分省数据,基于非期望产出SBM-DEA模型,测算了省际全要素能源效率和Malmquist生产率指数并将后者分解为技术变动和效率变动;以Malmquist生产率指数、技术变动和效率变动作为技术进步的代理变量,将技术进步对能源效率的影响分解为直接效应和间接效应,分别在邻接空间权重和地理距离权重下衡量了技术进步对能源效率的空间溢出效应。研究发现,中国的区域全要素能源效率存在显著的空间依赖性和空间异质性;技术进步对能源效率具有"双刃剑"特征,即技术进步对本区域能源效率均存在显著正向促进作用,但对其他区域均却存在显著的负向空间溢出效应;同时,技术变动的空间溢出效应明显大于效率变动的空间溢出效应。     

应用逐步回归分析方法研究经济问题的探索

回归分析方法是数理统计中主要方法之一,它根据数理统计原理,对各种现象变动的因果关系作定量的测定和分析,在各门科学中得到广泛的应用。不论在自然界或社会现象中,当被研究的若干变量之间存在依存关系,并具有随机性,就可以应用回归分析方法,测定其依存程度及其变动的规律性。由于客观现象之间的相互制约关系,每一种现象的变动,都是许多种因素共同作朋的结果,因此在应用回归分析方法时,主要是应用多元回归分析,它研究多个自变量对某一因变量的影响程度及其变动的规律性。     

我国信托公司投入产出效率区域差异比较

本文利用国内46家信托公司2005—2012年数据,基于DEA方法构建FAVAR模型,对不同地区信托公司的投入产出效率进行分析。研究表明:我国信托公司投入产出效率总体仍处于递增阶段,推动了信托业的快速发展;不同地区信托公司投入产出效率存在显著差异,企业景气指数、固定资产投资增速、地区经济增长、货币供给增速和利率等变量对效率变动的冲击最为显著。未来几年,我国信托公司规模效率增速都将降低,中部、西部地区的技术效率增速还将受到制约。但是,随着不同地区信托公司全要素生产率的持续提升,我国信托公司的潜在投入产出效率将在长期不断提高。     

海洋渔业资源捕捞量变动的结构分解与比较——以山东省为例

在构建的结构分解模型中将海洋渔业捕捞量变动分解为资源消耗强度变动效应、经济技术系数变动效应、最终需求水平变动效应、最终需求系数变动效应和最终需求分布变动效应等。根据山东省1997年和2007年的投入产出表提供的数据,运用构建的模型对该省近十年的海洋鱼类、软体动物和甲壳动物等三类海洋渔业资源捕捞量变动的因素分解效应进行了分析。结果表明:海洋渔业资源捕捞量下降与资源消耗强度变动效应、经济技术变动效应正相关,而与最终需求变动效应负相关;最终需求水平变动、最终需求系数变动和最终需求分布变动对三类渔业资源需求量变动均具有增量化作用,其中最终需求水平变动的增量化作用最明显;不论是减量化作用,还是增量化作用,鱼类资源需求的五类变动效应最为明显;经济技术变动效应的六部门分解效应中,工业部门的减量化作用最为明显,渔业和服务业部门的增量化作用最为明显。     

环境约束下吉林省工业生产绩效的区域分析

本文利用吉林省9个地市2004～2008年的投入产出数据,将数据包络分析模型与聚类分析相结合,测算了工业部门的环境技术效率,检验了地区工业环境技术效率的影响因素。研究结果显示:地区间生产绩效极不平衡,中西部地区工业环境技术效率较高,东部地区环境技术效率普遍较低;环境技术效率与集聚效应、科技投入强度呈正相关关系,与资本有机构成、政府影响力呈显著负相关关系。     

基于DEA模型的高等院校院系投入产出效率评估

建立高等院校院系投入产出效率评估的数据包络分析模型，进行DEA有效性分析和规模效益分析．测算出经济效益评价指标、松弛变量、各投入产出的权重系数等多项分析参数，并且根据各个院系的经营效益做出评价，以期为院系资源配置的合理性、资源利用的有效程度、导致经营无效的因素分析提供依据。     

空气污染程度与经济发展水平对人口死亡率的影响研究——基于向量自回归模型的实证分析

利用1983—2015年的时间序列数据,构建计量实证模型,采用协整分析和向量自回归等分析方法,实证研究人口死亡率、空气污染程度与经济发展水平之间的协整关系、格兰杰因果关系、脉冲效应以及方差分解,以探析空气污染程度与经济发展水平对人口死亡率的影响。研究发现:空气污染程度上升会导致人口死亡率增加,而提高经济发展水平则会降低人口死亡率,人口死亡率、空气污染程度与经济发展水平之间存在长期稳定的协整关系;人口死亡率、空气污染程度与经济发展水平之间存在单项的格兰杰因果关系,即空气污染程度与经济发展水平是人口死亡率的格兰杰成因;从脉冲效应和方差分解得出,空气污染程度的变动对人口死亡率产生较大的正作用,而经济发展水平的变动对人口死亡率产生较小的副作用。     

Modelling export equations using an unobserved component model: the case of the Euro Area and its competitors

This article analyses developments in the external sector for the Euro Area and its major competitors and quantifies the dynamic contributions of the key determinants of trade to export volume behaviour. In addition to the traditional variables affecting export volumes, price and foreign demand, an unobserved component in the form of a time-varying trend enters the export equations to capture underlying non-price competitiveness. The structural modelling approach used within an error correction framework allows isolating the different sources of trade fluctuations and to better assess the contribution of each set of variables to export flows. The findings confirm that stochastic trends are present as a result of technical change and other exogenous factors driving export flows, and that a failure to account for these trends will lead to biased estimates of long-run price elasticities.     

A comparison of proxy variable and stochastic latent variable approaches to the measurement of bias in technological change in south african agriculture*

Technical change is inherently unobservable and has conventionally been represented by proxy variables, from simple time trends to more sophisticated knowledge stock variables. This paper follows Lambert and Shonkwiler (1995) in modelling technical change as a stochastic unobservable variable and tests this formulation against the alternative of using R&D and patent indices. This is done by fitting a system of share equations, derived from the dual profit function, to production data for South African agriculture. Each equation includes both unobserved technical change components and technical proxy variables. Variable deletion tests show that conventional proxy variables fail to explain the biases of technological change, while cointegration tests show that technical change is both stochastic and biased. The latent variables provide estimates of biases that are consistent with past studies and the historical record and can be explained by policy change in South Africa following WWII. The demonstration of high rates of return to R&D is not sufficient to justify R&D activity when biased technological change exacerbates input use and welfare distortions within and without the sector. * We thank the University of Pretoria for funding the study and the referees and delegates for many useful comments.     

Examining the stochastic behavior of REIT returns: Evidence from the regime switching approach

In this paper the stochastic behavior of the returns on real estate investment trusts (REITs) is examined by using the unobserved component Markov switching (UC-MS) model. This approach endogenously permits the volatility to switch as the date and regime change and allows us to decompose the permanent and transitory components in REIT returns at monthly frequencies. The empirical evidence clearly shows that, for all of the REIT returns, the overall variance of the transitory component is significantly smaller than the corresponding variance for the permanent component. The durations of the high-variance regimes for both the fundamental and transitory components are short-lived and revert to normal levels quickly.     

Estimating Telephone Demand with State Decennial Census Data from 1970–1990

A telephone demand model (logit) is estimated with pooled Decennial Census data (1970, 1980 and 1990) for the states. Previous studies using pooled FCC penetration data are suspect due to large standard errors in the sample. Since our model includes data across time this allows the inclusion of long distance price and increases the variation in the standard variables. Time-effect dummy variables control for unobserved shifts in the data. Given that these dummy variables may pick up some of the effect of the long distance price, as well as other unobserved effects, their estimated impact is relatively small. Robust model results lead to the conclusion that elasticities decline through time. Furthermore, while subsidized penetration is more effective for targeted than untargeted programs, the cost per year of adding a household to the network is very high in either case (for 1990 about $5368 for untargeted; and for targeted $191 in 1990 and $1581 in 1998).     

APPLICATION OF PANEL DATA MODELS IN BENCHMARKING ANALYSIS OF THE ELECTRICITY DISTRIBUTION SECTOR*

ABSTRACT ** : This paper explores the application of several panel data models in measuring productive efficiency of the electricity distribution sector. Stochastic Frontier Analysis has been used to estimate the cost‐efficiency of 59 distribution utilities operating over a nine‐year period in Switzerland. The estimated coefficients and inefficiency scores are compared across three different panel data models. The results indicate that individual efficiency estimates are sensitive to the econometric specification of unobserved firm‐specific heterogeneity. This paper shows that alternative panel models such as the ‘true’ random effects model proposed by Greene (2005) could be used to explore the possible impacts of unobserved firm‐specific factors on efficiency estimates. When these factors are specified as a separate stochastic term, the efficiency estimates are substantially higher suggesting that conventional models could confound efficiency differences with other unobserved variations among companies. On the other hand, refined specification of unobserved heterogeneity might lead to an underestimation of inefficiencies by mistaking potential persistent inefficiencies as external factors. Given that specification of inefficiency and heterogeneity relies on non‐testable assumptions, there is no conclusive evidence in favour of one or the other specification. However, this paper argues that alternative panel data models along with conventional estimators can be used to obtain approximate lower and upper bounds for companies' efficiency scores.     

产业集聚、技术创新与环境污染——基于中国工业行业面板数据的实证分析

利用1999—2013年中国21个两位数工业行业的面板数据,利用面板数据向量自回归模型,实证分析了产业集聚、技术创新与环境污染的动态关系。结果表明:工业集聚程度的提高能够显著减少工业污染排放、促进技术创新;技术创新对环境污染排放具有显著的正向影响;环境污染排放具有循环累计因果效应;随着时间的推移,产业集聚对环境污染排放的抑制作用越来越明显,但长期内技术创新对环境污染波动的解释力将超越产业集聚。     

Sorting and inequality in Canadian schools

A student's peers are often thought to influence his or her educational outcomes. If so, an unequal distribution of advantaged and disadvantaged students across schools (“sorting”) in a community will amplify existing inequalities. This paper explores the relationship between the degree of sorting across schools within a community and educational inequality as measured by the variance of standardized high school exam scores within the community. Cross-sectional OLS estimates suggest that the variance of test scores is related to sorting by ethnicity, but not to sorting by income or parental education. We then implement two strategies for addressing endogeneity in the degree of sorting: a standard unobserved effects (first-difference) approach, and a first-difference/instrumental variables approach in which the structure of school choice (number and relative size of schools) is used to construct instruments for the degree of sorting. The results from both approaches indicate that the variance of test scores is related to sorting by home language and parental education, but not to sorting by income. Our results also suggest that reducing sorting would have little effect on inequality of outcomes in the typical Alberta community, but would have substantial effects in the larger cities.     

Fair ranking of teachers

Economic theory suggests that it is optimal to reward teachers depending on the relative performance of their students. We develop an econometric approach, based on stochastic frontier analysis, to construct a fair ranking that accounts for the socio-economic background of students and schools and the imprecision inherent in achievement data. Using German PIRLS (IGLU) data, we exploit the hierarchical structure of the data to estimate the efficiency of each teacher. A parsimonious set of control variables suffices to get a “fair” estimate of unobserved teacher quality. A Hausman–Taylor type estimator is the preferred estimator because teacher efficiency and some exogenous variables may be correlated.     

金融结构差异与货币政策传导的区域效应

作为货币政策体系中最为关键和核心的环节——货币政策的传导对货币政策效应的发挥具有重要作用。文章在分析我国区域金融结构差异的基础上,利用面板向量自回归模型(PVAR)对保费收入、股本融资以及银行信贷规模等变量进行脉冲响应分析和方差分解,检验了区域金融结构差异对货币政策信贷传导的重要影响。数据分析和模型检验发现保费收入、股本融资等区域金融结构间的变量差异在统一货币政策传导中存在着非对称性,我国货币政策传导存在着较为显著的区域效应。改善货币政策调控的经济效应,提高货币政策传达的效率,需要政府在制度和政策方面完善区域间巨大的金融结构差异。     

Efficiency Measurement in Network Industries: Application to the Swiss Railway Companies

The persistence of increasingly high government subsidies in Switzerland’s railroads has led the federal and cantonal authorities to discussing the possibility of high-powered incentive contracts such as those based on cost efficiency benchmarking. Railways are however, characterized by a high degree of unobserved heterogeneity that could bias the efficiency estimates. This paper examines the performance of several panel data models to measure cost efficiency in network industries. The unobserved firm-specific effects and the resulting biases are studied through a comparative study of several stochastic frontier models, applied to a panel of 50 railway companies operating over a 13-year period.* The authors wish to thank Michael Crew and two anonymous referees for their helpful suggestions. Aurelio Fetz provided an excellent assistance, which is gratefully acknowledged. Any remaining errors are the responsibility of the authors.This revised version was published in June 2005 with corrections in the author affiliations.