Hub location problems in transportation networks

In this paper we propose a 4-index formulation for the uncapacitated multiple allocation hub location problem tailored for urban transport and liner shipping network design. This formulation is very tight and most of the tractable instances for MIP solvers are optimally solvable at the root node. While the existing state-of-the-art MIP solvers fail to solve even small size instances of problem, our accelerated and efficient primal (Benders) decomposition solves larger ones. In addition, a very efficient greedy heuristic, proven to be capable of obtaining high quality solutions, is proposed. We also introduce fixed cost values for Australian Post (AP) dataset.     

The impact of the introduction and use of an informational website on offline customer buying behavior

Do customers increase or decrease their spending in response to the introduction of an informational website? To answer this question, this study considers the effects of the introduction and use of an informational website by a large national retailer on offline customer buying behavior. More specifically, we study a website's effects on the number of shopping trips and the amount spent per category per shopping trip. The model is calibrated through the estimation of a Poisson model (shopping trips) and a type-II tobit model (the amount spent per category per shopping trip), with effect parameters that vary across customers. For the focal retailer, an informational website creates more bad than good news; most website visitors engage in fewer shopping trips and spend less in all product categories. The authors also compare the characteristics of shoppers who exhibit negative website effects with those few shoppers who show positive effects and thus derive key implications for research and practice.     

我国个人所得税再分配效应及累进性的实证分析

税收是调节收入分配差距的有效手段之一。本文循着层层递进的逻辑,建立了税收再分配效应及累进性分解的数学理论模型,实证分析了1995年到2008年间我国个人所得税的再分配效应,剖析了影响其变动的深层次原因。结果表明:除2006年外,我国个人所得税起到了正向、且进一步加强的再分配效应,但调节效果非常有限;平均税率明显偏低,累进性基本呈下降趋势;分类征收模式导致总体累进性下降,工资薪金所得税是个人所得税累进性的主要来源;免征额在工资薪金所得税的累进性中起主导作用,其次是税率结构,而社会保障支出起较小的累进(或累退)效果。因此,在公平视角下改革与完善我国个人所得税制迫在眉睫。     

宏观经济运行质量评价指标的选择方法

筛选指标的传统方法或者是定性分析或者是单一的定量分析。本文收集了37个反映宏观经济运行质量的指标信息,依据相关系数及其聚类分析,将相关程度不同的指标聚为不同的组或类,然后在相关系数高度相关的指标组进行因果关系分析,选取那些作为原因的变量或指标。利用相关时间序列建模方法中的向量自回归模型,及其脉冲响应函数和方差分解分析,进一步区分那些影响其他变量的重要变量。最后得到一组既能反映现象变化,又是主要或重要变量的14个指标。这一指标筛选方法不同于传统方法,它充分利用了指标之间的关联信息、因果信息和动态相依信息,具有综合性与实用性。     

Decomposition of energy-related CO2 emission over 1991-2006 in China

This paper presents a decomposition analysis of energy-related CO₂ emission in China for the period 1991-2006 divided into three equal time intervals. The complete decomposition method developed by Sun is used to analyze the nature of the four factors: CO₂ intensity, energy intensity, structural changes and economic activity. The results show that economic activity has the largest positive effect in CO₂ emission changes in all the major economic sectors and China has achieved a considerable decrease in CO₂ emission mainly due to the improved energy intensity. However, the impact of CO₂ intensity and structural changes is relatively small. Structural changes only exhibit positive effect to the CO₂ mitigation in agricultural sector, and CO₂ intensity also contributes to the decrease of CO₂ emission in transportation sector. Moreover, a formula about CO₂ mitigation is presented in this paper, which shows that China has made a significant contribution to reducing global CO₂ emission.     

持久收入假说与我国城镇居民消费——基于省级面板数据的实证分析

运用基于持久收入和暂时收入的两种分解方法的省际面板模型检验持久收入假说的三个假设.结果发现,我国城镇居民消费与持久收入和暂时收入均存在显著的相关关系,暂时收入的边际消费倾向不为零;就诸省份而言,暂时收入的边际消费倾向不同.进一步探讨了持久收入假说不能完全解释我国城镇居民消费行为的原因."λ假说"检验表明,城镇居民消费对当期收入过度敏感,其呈现理性化趋势.     

中国人力资本水平与FDI技术溢出关系研究

针对1985-2009年间中国人力资本水平和FDI技术溢出进行VECM模型检验结果表明,我国人力资本水平与FDI技术溢出存在长期稳定关系,但短期关系不显著。从动态层面看,FDI技术溢出变化对我国人力资本水平有显著的正向影响,但我国人力资本水平变化对FDI技术溢出的正向影响程度较弱。     

人民币实际汇率波动对中欧进出口贸易影响的实证研究

本文通过建立GARCH模型量度了人民币对欧元实际汇率的波动性,并运用协整检验模型、误差修正模型、脉冲响应函数和方差分解技术就人民币实际汇率变动对中国与欧元区之间进出口贸易的影响进行分析。分析结果表明,中国对欧元区出口在长期内随汇率波动而增加,而进口却随汇率波动而减少;在短期内汇率波动推动中国进口,抑制中国出口。人民币升值在长期内给双边出口均造成伤害,但对中国出口伤害更大;在短期内人民币贬值将对中国进出口均有推动作用。本文分析还表明,在长期内,中国对欧元区出口收入效应远远大于欧元区对华出口收入效应;在短期内,中国实际收入变动对欧元区出口表现负向冲击,而欧元区实际收入变动对中国出口表现为正向冲击。中国汇率制度改革对中国出口欧元区产生推动作用,对欧元区出口产生抑制作用,且前者大于后者。实际汇率水平及其波动性变化对欧元区对华出口变动的解释力高于中国实际收入水平变化的解释力,而对于中国对欧元区出口的变动,欧元区实际收入水平变动的解释力高于实际汇率水平及其波动性变化的解释力。     

An analysis of real-estate risk using the present value model

The current study uses a present value model that allows for a time-varying expected discount rate in conjunction with a VAR process to decompose real-estate risk. The study finds that the variance ofunexpected returns accounts for most of the total risk with cash-flow risk accounting for twice as much of the unexplained real-estate risk although discount rate risk is also an important factor. This dominance of cash-flow risk is found to result in a weaker mean reversion process for real estate relative to stocks. Another finding is that real estate investors tend to become apprehensive about the future when news on future cash flow is good, and thus they demand higher expected future returns.     

The Inequality of Regional Economic Development in China between 1991 and 2001

This paper measures the unequal development of the regional economies in China and investigates the primary factors leading to the inequality. The official data on China's regional GDP and the regional GDP of three industrial sectors from 1991–2001, as reported in the China Statistical Yearbook and A Statistical Survey of China, are adopted to calculate and decompose the Gini coefficient for each year. The primary finding is that the levels of inequality in China's regional economies clearly showed a slight upward trend after 1991. The inequality of the overall GDP is primarily attributed to the between-group effect rather than to the within-group effect. It is also found that the regional inequality of the secondary industry sector's development accounted for half of the overall inequality. Thus, this study suggests that it is crucial for China to formulate and adhere to policies that will help it to develop the economy more equally among all areas and to develop the secondary industry sector among all regions/provinces in order to overcome the important issue of the inequality in regional economic development.