外贸商品结构合理性评价指标的构建及实证研究

文章立足国情,在界定外贸商品结构合理性涵义的基础上,确立了以是否符合产业结构的改善和经济发展的需要为合理性的判断标准,以求克服盲目追求外贸商品结构高级化的弊端。在比较现有研究方法的基础上选择投入产出分析法,运用改进后的影响力系数和推动力系数,重新构造了进出口商品结构合理度指数和调整指数,并利用1997年、2002年和2007年的中国投入产出表计算了相关的评价指标,对我国近10年来的进出口商品结构合理性进行分析,发现我国的外贸商品结构合理度呈先扬后抑的趋势,说明其合理性有待改进,最后依据结论提出了调整我国外贸商品结构合理化的对策。     

我国制造业进出口隐含污染分析:基于投入产出的方法

使用非竞争型投入产出表,核算了我国1976-2004年制造业28个行业6种污染物进出口隐含污染的BEET指标值和PTT指标值,并分析了我国进出口隐含污染的规模效应和结构效应。研究结果表明,我国进口和出口的规模效应为正且逐年增长,20世纪90年代以后出口规模效应逐渐大于进口规模效应;出口的结构效应基本小于零,进口的结构效应不明确,我国的产业结构调整和升级可能有利于减少我国进出口的净隐含污染量。此外,制造业出口隐含污染主要来源于纺织、塑料、机械设备和工业化学这四个行业。     

银行效率实证研究的投入产出指标选择

评述了近年来有关重点文献中银行效率测算时投入产出指标选择的共性问题,如指标的重复与遗漏、对应股东权益的资本价格统计口径偏误等;与大多数文献一样依据中介法的思想,针对不同的测算目的建立了相应的投入产出指标体系,并明确了各项指标在财务报表中对应的项目;对我国全部16家上市银行近6期数据的实证表明使用三套评价指标体系测算的效率结果大体上一致。     

“多项连乘和加总”的因素分解法在能源平衡表中的应用

本文对各种研究方法进行分类比较,并指出它们之间的相通性;接着指出在实证研究中普遍存在由于经济部门、产业结构、能源种类等划分的宽口径带来的实验误差：宽口径处理方法的盛行一方面是由于详尽数据的获得存在难度;另一方面,是因为国内外现有研究都是采取“单项连乘和”的形式,这极大限制了分解表达式的涵盖范围和因子种类。为了克服实证研究误差,本文提出将“单项连乘和”扩展成“多项连乘和的加总”形式,并对这种新的方程形式进行因素分解的计算和求解,最后将新方法运用到北京市2000年-2011年的能源平衡表中,分解终端能源消费,获得了细致合理的实验结果。     

增加值率下降意味着什么

增加值率是从总体上度量一个经济体投入产出效益的综合指标。中国的增加值率一直在下降,表明中国经济增长的质量在下降。本文定义了中间投入贡献系数,给出其与增加值率的关系,通过分析中间投入贡献系数的变化本文得出,新增加中间投入品的贡献系数下降是造成总体中间投入贡献系数进而增加值率下降的原因。接着本文利用变参数经济计量模型,测算了改革开放以来国内中间投入和进口中间投入的贡献系数的数值和变化情况,并就提高增加值率的可能方面进行了探讨。     

The economic impact of shale gas extraction: A review of existing studies

Recent advances in drilling technology have allowed for the profitable extraction of natural gas from deep underground shale rock formations. Several reports sponsored by the gas industry have estimated the economic effects of the shale gas extraction on incomes, employment, and tax revenues. None of these reports has been published in an economics journal and therefore have not been subjected to the peer review process. Yet these reports may be influential to the formation of public policy. This commentary provides written reviews of several studies purporting to estimate the economic impact of gas extraction from shale beds. Due to questionable assumptions, the economic impacts estimated in these reports are very likely overstated.     

Technological change in energy systems: Learning curves, logistic curves and input-output coefficients

Learning curves have recently been widely adopted in climate-economy models to incorporate endogenous change of energy technologies, replacing the conventional assumption of an autonomous energy efficiency improvement. However, there has been little consideration of the credibility of the learning curve. The current trend that many important energy and climate change policy analyses rely on the learning curve means that it is of great importance to critically examine the basis for learning curves. Here, we analyse the use of learning curves in energy technology, usually implemented as a simple power function. We find that the learning curve cannot separate the effects of price and technological change, cannot reflect continuous and qualitative change of both conventional and emerging energy technologies, cannot help to determine the time paths of technological investment, and misses the central role of R&D activity in driving technological change. We argue that a logistic curve of improving performance modified to include R&D activity as a driving variable can better describe the cost reductions in energy technologies. Furthermore, we demonstrate that the top-down Leontief technology can incorporate the bottom-up technologies that improve along either the learning curve or the logistic curve, through changing input-output coefficients. An application to UK wind power illustrates that the logistic curve fits the observed data better and implies greater potential for cost reduction than the learning curve does.     

投入产出表和社会核算矩阵更新研究评述

本文对投入产出(IO)表和社会核算矩阵(SAM)更新方法进行了归类和比较评述。主要观点:第一,已有的IO表或SAM更新方法主要分为统计学方法、优化法和宏观经济学分析方法;第二,以现代经济学为基础的更新技术应引起高度重视;第三,在非普查年份,统计部门应制度化地开展重点IO系数调查,并将相关数据及时公开化;第四,在实际操作中应正确认识更新中已知信息的地位,并注意更新中的保号性问题。     

Thermodynamics and process analysis for future economic scenarios

Economists are increasingly interested in forecasting future costs and benefits of policies for dealing with materials/energy fluxes, polluting emissions and environmental impacts on various scales, from sectoral to global. Computable general equilibrium (CGE) models are currently popular because they project demand and industrial structure into the future, along an equilibrium path. But they are applicable only to the extent that structural changes occur in or near equilibrium, independent of radical technological (or social) change. The alternative tool for analyzing economic implications of scenario assumptions is to use Leontief-type Input-Output (I-O) models. I-O models are unable to endogenize structural shifts (changing I-O coefficients). However, this can be a virtue when considering radical rather than incremental shifts. Postulated I-O tables can be used independently to check the internal consistency of scenarios. Or I-O models can be used to generate scenarios by linking them to econometric macro-drivers (which can, in principle, be CGE models). Explicit process analysis can be integrated, in principle, with I-O models. This hybrid scheme provides a natural means of satisfying physical constraints, especially the first and second laws of thermodynamics. This is important, to avoid constructing scenarios based on physically impossible processes. Process analysis is really the only available tool for constructing physically plausible alternative future I-O tables, and generating materials/energy and waste emissions coefficients. Explicit process analysis also helps avoid several problems characteristic of pure CGE or I-O models, viz. (1) aggregation errors (2) inability to handle arbitrary combinations of co-product and co-input relationships and (3) inability to reflect certain non-linearities such as internal feedback loops.     

Assessment of regional trade and virtual water flows in China

The success of China's economic development has left deep marks on resource availability and quality. Some regions in China are relatively poor with regards to water resources. This problem is exacerbated by economic growth. Flourishing trade activities on both domestic and international levels have resulted in significant amounts of water withdrawal and water pollution. Hence the goal of this paper is to evaluate the current inter-regional trade structure and its effects on water consumption and pollution via ‘virtual water flows’. Virtual water is the water embedded in products and used in the whole production chain, and that is traded between regions or exported to other countries. For this assessment of trade flows and effects on water resources, we have developed an extended regional input-output model for eight hydro-economic regions in China to account for virtual water flows between North and South China. The findings show that the current trade structure in China is not very favorable with regards to water resource allocation and efficiency. North China as a water scarce region virtually exports about 5% of its total available freshwater resources while accepting large amounts of wastewater for other regions' consumption. By contrast, South China a region with abundant water resources is virtually importing water from other regions while their imports are creating waste water polluting other regions' hydro-ecosystems.