交通基础设施、空间溢出与全要素生产率——基于丝绸之路经济带面板数据的空间计量分析

本文立足于多种经济增长理论，以“丝绸之路经济带”沿线14省为研究对象，选取多维要素的空间面板数据，在经济、地理与邻接三种空间权重下通过构建空间杜宾模型估计交通基础设施与相关控制变量对区域全要素生产率的作用机理及空间溢出效应。结果表明：2000~2015年丝绸之路经济带沿线省份整体交通运输能力对区域全要素生产率正向溢出效果明显，铁路与高级公路密度次之，交通基础设施投资效果不佳。除此之外，交通基础设施直接效应远大于间接效应，对本区域全要素生产率的提高促进作用明显。最后从研究样本整体和个体角度有针对地提出促进丝绸之路经济带全要素生产率持续增长的对策。     

交通基础设施、空间溢出效应与物流产业效率——基于“丝绸之路经济带”西北5省区的实证研究

在经济增长理论、运输经济理论和经济地理理论的基础上，探究了交通基础设施对物流产业效率时空演变与空间溢出效应的影响机理。基于2005～2015年“丝绸之路经济带”西北5省区的面板数据，采用SFA模型测算物流产业效率，并运用空间面板计量方法实证检验了交通基础设施对物流产业效率的空间溢出效应。实证研究的结果表明：“丝绸之路经济带”西北5省区的物流产业效率存在一定的差异但是整体效率在不断提升，邻省交通基础设施水平和本省交通基础设施水平都对本省的物流产业效率具有显著的正向溢出效应，以期为物流产业效率问题研究提供一定的理论评价参考。     

Determinants of spatial market efficiency of grain markets in Russia

Results of an unobserved effects model on the determinants of inter- and intraregional grain market integration in Russia in comparison to the USA highlights the differences of the mechanisms underlying market integration in each market. Physical trade flows are exclusively dominant in Russia; in contrast, in the United States, additional information flows induced by commodity futures markets play a great role. Policies which improve grain market efficiency in Russia should not only foster investments in transportation and trade infrastructure, but also the development of market information services and commodity futures markets.     

Human capital matters: Market valuation of firm investments in training and the role of complementary assets

Research summary: This article empirically examines the economic value to firms of investing in the training of their employees and firm‐level factors that influence how much the firms benefit. Event study methodology is used to obtain a measure of the economic impact of information regarding a firm's human capital management investments and policies. Subsequent regression analyses are then used to test hypotheses regarding possible complementary relationships between firm‐level factors and human capital investments. Results provide robust support for the proposition that effective investments in human capital and training matter, and that these human capital investments are more impactful when combined with complementary assets of R&D, physical capital, and advertising investments . Managerial summary: Do firm investments in training and the development of employee human capital matter with regard to financial performance? We find that, yes, these investments do matter. Our results show that managers who view employee human capital as an asset to be invested in and developed can expect to outperform those who view it as a cost to be minimized. In addition, we find that these human capital investments will be of even greater economic value to firms when they have made complementary investments in R&D, physical capital, and advertising . Copyright © 2016 John Wiley & Sons, Ltd.     

The impacts of hybrid maize seed on the welfare of farming households in Kenya

This paper explores the impacts of hybrid maize adoption on the welfare of farming households in Kenya. We use a four-year panel dataset to estimate the effects of hybrid seed use on four indicators of household welfare, namely, income, assets, inequality and poverty. Results show that use of hybrid seed not only contributes to higher annual income, but also to raising the value of assets, possibly reflecting longer-term welfare effects. Further, we find that use of hybrid seed reduces the depth of poverty, and that the amount planted reduces inequality. As expected, impacts differ between major and minor maize-growing areas of the country. Maize farmers who do not use hybrid seed are clearly disadvantaged. This calls for continued public and private investments in the infrastructure and policy process that supports a competitive, liberalized seed industry and improved access of smallholder farmers to well-adapted, affordable hybrids.     

Rising real wages,mechanization and growing advantage of large farms: Evidence from Indonesia

This paper examines dynamic patterns of land use, capital investments and wages in agriculture using farm panel data from Indonesia. The empirical analysis shows that with an increase in real wages that prevailed in both agricultural and non-agricultural sectors in rural areas, relatively larger farmers increased the size of operational farm land by renting in land as well as used more hired-in machines through machine rental and/or service providers, which induces the substitution of labor by machines. Machines and land are complementary and, consistently, the inverse farm size-productivity relationship tends to be reversed among relatively large holders. The results support growing (diminishing) advantage of large (small) farms in the presence of rapidly rising real wages and have food security policy implications to many Asian countries where real wages are rapidly rising and small farms are predominant.     

Rolling out of fibre optic networks in intermediate versus urban areas: An exploratory spatial analysis in the Netherlands

Within the growing literature on broadband development, much research has focused on infrastructure competition and spatial effects driving investment incentives in broadband provision. However, less attention has been paid to the geographical factors explaining very high capacity fibre based network rollout. The purpose of this paper is to examine these geographical effects of rollout of these networks by utilizing basic data mining techniques in conjunction with exploratory spatial data analysis. In explaining the rollout of these networks, the paper derives from the literature a geographical model on broadband provision and examines it empirically by focusing on the spatial and temporal effects driving very high capacity fibre-based network development in the Netherlands. The paper confirms previous research on market uncertainty and the techno-economics of broadband development, but shows, in addition, that more specific factors related to local effects and demand uncertainty are vital in explaining the rollout of very high capacity fibre-based network.     

物流产业集聚对制造业劳动生产率的影响机理研究——基于空间杜宾模型

本文利用2006~2015年我国30个省份（西藏除外）的面板数据，基于空间杜宾模型分析物流产业集聚对我国制造业劳动生产率的作用及空间溢出效应。结果表明，物流产业集聚、物流劳动生产率、外商直接投资、交通基础设施、地方政府投资等影响因素的直接效应与间接效应的方向与显著性均存在差异性。从总效应来看，物流产业集聚与地方财政支出均显著为正，是制造业劳动生产率提升的重要源泉。外商直接投资显著为负，一定程度上抑制我国制造业劳动生产率的提高。     

综合运输体系对区域经济空间格局变迁的影响与优化研究

文章从梳理国内外研究进展为切入点,探讨了综合运输体系的发展完善及动态变化对区域经济空间格局的影响,提出了优化的途径与策略。文章认为,交通运输在区域经济空间结构的变化中处于重要的先导地位,应通过推进交通基础设施集约化发展、提高公共交通分担率、大力发展绿色交通、建立"政府——企业——公众"三方治理模式等措施全力优化综合运输体系与区域经济空间格局之间的关系。     

城市交通低碳发展策略的系统动力学分析——基于土地利用视角

随着城市环境的恶化,城市低碳交通建设迫在眉睫。本文从土地利用角度构建城市交通碳排放与土地利用的系统动力学模型,得出城市交通低碳发展的两种策略,并以长春市为例,对两种策略方案进行了仿真分析。结果表明,提高土地利用强度和增大土地混合利用程度均能使交通碳排放减少,而且增加土地多样性程度的实施效果要优于土地利用强度的提高。     

Explaining smallholder maize marketing in southern and eastern Africa: The roles of market access,technology and household resource endowments

Research on household food grain sales behavior in developing countries has tended to focus on the roles of market access and prices to explain why many rural households do not sell staple crops, though recent literature suggests that low household asset endowments may also be key constraints. We use econometric analysis of panel data from smallholders in Kenya, Mozambique, and Zambia to inform the design of public investments that will enable smallholders to increase their maize sales. Results show that investments that raise farm-level productivity and land access are an essential complement to investments that improve market access.     

Nanotechnology for enhancing food security in India

A framework for assessment of the potential of nanotechnology for enhancing food security in India is developed. Agricultural productivity, soil health, water security, and food quality in storage and distribution are identified as the primary determinants of food security that can be impacted by developments in nanotechnology. The framework is developed in two stages: (i) mapping nanotechnology to agri-food thematic areas across the agricultural value chain and (ii) from the thematic areas to the food security determinants. Using published literature and patents data, a model to organize and map nanotechnology research to the agri-food thematic areas and food security determinants is developed through a specially designed database. The model allows identification and prioritization of potential areas for nanotechnology applications to enhance food security. Comparisons of this technology with green revolution technologies and agricultural biotechnology indicate a possibility of greater and faster impact on all components of the agri-value chain with concurrent social, ethical, legal and environmental implications. There is a need for investments in capacity building and development of an agri-nanotechnology infrastructure in India, and for ex ante assessment of its implications for society.     

Japan׳s prefectural digital divide: A multivariate and spatial analysis

This study of the digital divide within Japan utilizes data from the country׳s 47 prefectures for multivariate and spatial analysis of distributions of information and communication technology (ICT) variables. The paper constructs an exploratory conceptual model of technology utilization and expenditures in Japan, induced from prior literature. Ten dependent ICT utilization and expenditure factors are posited to be related to 12 independent demographic, economic, infrastructure, education, innovation and openness factors. The relationship of the independent to dependent factors is moderated by analysis of spatial patterns of technology utilization to examine proximities and reduce spatial bias. Based on the model, a multivariate analysis identifies correlates of the nation׳s digital divide, including patents registered by Japanese citizens, newspaper circulation, students and pupils per capita, household expenditures on education, rural/urban status, and Japan׳s aged population structure which has wide generational gaps. Spatial clusters and outliers of ICTs in prefectures are analyzed, with attention to their policy impacts. Findings suggest modifications to the conceptual model. Implications of findings for the country׳s official national technology planning policies are considered and recommendations made to expand them.     

Food security and public agricultural spending in Bolivia: Putting money where your mouth is?

This paper explores the reduction of food insecurity in Bolivia, adopting a supply-side approach that analyzes the role of agricultural spending on vulnerability to food insecurity. Vulnerability to food insecurity is captured by a municipal-level composite indicator for all 327 municipalities in 2003, 2006, and 2007. Econometric analysis indicates that levels of public agricultural spending are positively associated with high or very high vulnerability—especially investments in infrastructure and research and extension. The authors interpret this to indicate that agricultural spending allocation is driven by high or very high vulnerability levels, but has small effects on reducing high vulnerability.     

新型和传统基础设施建设耦合协调:时空格局、地区差异与驱动因子

本文构建了新型和传统基础设施建设评价指标体系,分别对中国各省(区、市)的新型和传统基础设施建设水平进行评价,并基于耦合协调模型测度新老基建耦合协调程度,最后采用空间杜宾模型探究两者耦合协调度的驱动机制及空间溢出效应。结果表明:(1)2011~2019年全国各省(区、市)耦合协调度平均水平呈现稳步上升趋势;耦合协调度的区域差异呈现波动上升的趋势,其中东部地区的区域内差异是造成全国整体差异的主要原因;(2)我国省域新旧基建的耦合协调等级呈现东强西弱的空间格局,且耦合协调等级的省际差异有逐年缩小的趋势;高值集聚区域全部分布在福建、浙江、江苏等东部沿海区域,低值集聚区主要分布在新疆、西藏、青海及宁夏一些西部相对落后地区,且低值集聚区的数量呈现先降低后上升的“V型”变化;(3)全国各省(区、市)新老基建耦合协调存在显著的空间相关性,财政支出水平、市场化、城市化、产业结构及利用外资等因素均对新旧基建的耦合协调水平产生了明显的驱动作用。     

On the Effects of Uncertainty on Investment Timing and Option Value

This article demonstrates that when the relationship between systematic risk and project value is taken into account, the sensitivity of investments with respect to volatility changes dramatically. By taking cash flows as a fundamental variable, the article shows that the value of an option to invest can be decreasing in volatility, contradicting the conventional wisdom. Second, the recent proposition, according to which the expected time to invest is U-shaped, does not generally hold; the expected time and the cash flow trigger are likely to be always increasing in volatility.     

肯尼亚电力投资的机会与风险

肯尼亚电力工业基础设施落后，电力严重短缺，电网运行不稳定。为保证电力工业以每年8％的速度发展，政府鼓励国外资本在电力、电信和交通等行业进行投资，并采取了相应的保护措施，但由于肯尼亚同中国具有不同的文化背景和法律体系，在肯尼亚进行电力行业的投资，风险与机遇并存。     

On the use of the Financial Option Price Model to Value and Explain Vacant Urban Land

This paper reviews the financial option model of under-utilizing urban land, with primary attention to the question of whether and how the model might move beyond the academic realm toward practical and quantitative applications. It is argued that the theoretical underpinnings that give the option model such power in the financial securities field do not extend to land applications, making it more important to justify the model empirically. Numerical analysis using a "decision analysis" type model of land option value is used in the paper to help guide and focus such empirical study. It is noted that while the option model focuses primary attention on uncertainty in future building values as the cause of land being held undeveloped, previous deterministic models focused on expected future growth in such values as the main cause for land speculation. As these two causes can have different policy implications, it would be desirable to use empirical analysis to gauge their relative importance. A strategy for empirically testing the option model of land is suggested, and concludes that definitive empirical tests will be difficult to achieve, in part because of the subjective nature of many of the model inputs.     

Strategic investments under competition for access provision

We examine competition for access provision when symmetric vertically integrated firms invest in infrastructure upgrades. Spillovers through access have two effects (a wholesale-profit effect and a retail-production effect) on infrastructure investment made by vertically integrated firms. When the vertically integrated firms freely set access charges, due to the dominance of the wholesale-profit effect, quality differentials endogenously occur between these firms (asymmetric equilibria). When access charges are regulated, symmetric equilibria occur with multiple equilibrium investments due to the retail-production effect. Because competition for access provision induces a strong incentive for infrastructure investment, it also achieves a higher social welfare than does access regulation.     

Assessing farm performance by size in Malawi,Tanzania, and Uganda

Many Sub-Sahara African countries have long endured sluggish agricultural productivity growth and a farm structure dominated by smallholders. This prevailing structure has led to public policies focusing on access to land and its distribution as ways to boost agricultural supply. Drawing on data from the Living Standards Measurement Study–Integrated Surveys on Agriculture (LSMS-ISA) for three East African countries (Malawi, Tanzania, and Uganda), our purpose is to: test whether smaller farms in these countries are more productive than larger ones; examine how managerial performance varies with farm size; and assess how public policy may improve farm performance. We adopt the Random Parameters Stochastic Production Frontier model to estimate and then decompose Total Factor Productivity (TFP) across different farm size classes. In doing so, we test for possible measurement errors of farmer self-reported land area using Global Positioning System (GPS) data, and explore the imperfect factor markets hypothesis. The results show that across the three countries TFP is higher for smaller farms than for larger ones. Overall, managerial performance is low suggesting that programs designed to enhance managerial capacity would promote farm productivity across all sizes. Other policies are size specific. Access to agricultural input markets improves the productivity of the small farms, while greater spending on transportation infrastructure and extension services enhances the productivity of the large.