地方政府债务空间与空间债务——基于地根经济的区位黏性视角

本文从人口流动的区位黏性这一全新视角，将地方政府性债务的李嘉图等价命题纳入新经济地理研究框架进行理论分析。为了进一步揭示理论模型的政策含义，采用空间计量方法验证沿海地区地方政府性债务的局部正相关特征。最优的债务政策取决于经济系统的初始条件，在非对称经济结构已经存在的情况下，单纯建设本地区的基础设施只会降低区域内的交易成本，这对于那些仅着眼于投巨资用于城市“硬件”建设的地方政府来说显然是一叶障目。建议依靠基础设施网络提高区域协同创新能力，培育规模报酬递增的专业化产业集群。     

Effects of scale economies and production seasonality on optimal hub locations: the case of regional fresh produce aggregation

Interest in supporting local and regional food systems is rising and food hubs have attracted considerable attention among Federal, State, and local policymakers. This study explores the problem of endogenous hub location in fresh produce value chains in the Northeastern United States. To overcome limitations in the literature, we incorporate the effects of economies of scale and production seasonality into our models. Three experimental models are designed to examine the effects of alternatively applying yearly, quarterly, and monthly data on model solutions. We explicitly assess how interactions of scale economies and seasonality influence the structure and spatial attributes of an optimal regional produce aggregation hub system. The three models generate marketed different solutions and in many respects they lead to different conclusions about developing local/regional supply chains. The monthly model allows for production seasonality and actual hub operation cycle frequency and thus leads to more efficient hub solution with rich policy implications.     

长江经济带中三角地区农业结构的分析与优化对策

[目的]从宏观、中观和微观3个层面深入分析长江经济带中三角地区湖北、湖南和江西3省的农业产业结构及其各产业差异性和相对优势及其竞争力。[方法]在宏观层面运用了传统的基尼系数分析3个省份历史发展上的地区经济水平差异,判断3个地区经济发展是否存在虹吸效应;从中观层面运用区位熵指数分析法分析区域农业产业结构,从农畜林渔等方面判断各区域产业专业化水平程度;从微观层面运用偏离—份额分析法(SSM)分离出3个地区的各部门产业的优势及其竞争力。[结果]区域内的经济差异变化呈不断增大的趋势,基尼系数不断扩大;湖北的种植业、渔业和农林牧渔服务业,湖南的种植业、林业、畜牧业和农林牧渔服务业,江西的林业、渔业都较中三角地区对应的子产业的区位熵指数高;江西木材和竹加工业和烟草业具有较大的产业竞争优势,湖北的茶叶、水产和瓜果疏菜产业优势明显,湖南地区农业产业综合优势主要在于烟草、水果、肉类以及木材和竹类加工业。[结论]通过比较地区农业产业竞争优势,提出发展地区产业特色,合理布局全域农业产业,提高农产品附加收益,稳固对结构优化的资金支持等对策建议。     

The effect of shared auditors in the supply chain on cost stickiness

Do supply chain audits have real effects?We focus on the effect of shared auditors in the supply chain on corporate cost stickiness.When a supplier shares audit...     

采用目标假设的三被动式传感器数据关联算法

被动式传感器目标跟踪是多传感器多目标跟踪领域的一个重要研究方向。针对三被动式传感器多目标定位系统全局最优数据关联的三维分配问题，在允许传感器漏检和虚警的情况下，通过分析拉格朗日松弛算法，提出一种假定真实目标的快速收敛算法。该算法通过粗关联假定真实目标并重新修改代价矩阵，然后进行细关联，使得拉格朗日松弛算法在保证关联精度的前提下有效地提高了收敛速度。理论分析和实验结果表明，该算法提高了数据关联的速度,并在一定程度上提高了关联准确率。     

Geography and capital structure

We investigate the impact of geographic location on firms’ capital structure decisions. We find strong evidence that location of a firm influences its capital structure. In particular, we find that centrally located firms have lower leverage ratios than do remotely located ones. Moreover, consistent with the hypothesis that those remotely located firms face more severe adverse selection problems, the effect of geographic location on capital structure is more pronounced when information asymmetry is higher. We further examine alternative explanations of the negative relation between firm geographic proximity and capital structure and show that the financial constraint effect and industry clustering effect do not explain our results. Copyright © 2016 ASAC. Published by John Wiley & Sons, Ltd.     

中国海外耕地投资的区位特征及其影响因素*——基于2000—2016年土地矩阵网络数据

［目的］分析中国海外耕地投资的区位特征及其影响因素，以促进我国海外耕地投资的合理布局，提高农业投资效率。［方法］以2000—2016年中国137宗海外耕地投资项目及其所涉及的35个东道国作为研究样本，运用Spearman相关分析方法，分别以耕地投资面积和耕地投资项目数量作因变量，研究其与各影响因素的相关关系，并用对应分析法进一步探究各东道国的相对优势。［结果］（1）我国海外耕地投资区域集中在东南亚且由周边国家向外扩展，被投资耕地用途多样，投资规模自2004年开始急剧上升，近年来呈下降趋势。（2）我国海外耕地投资以效率寻求型和市场寻求型为主，倾向于资源丰富、与我国距离较近、制度相似、经济关系良好但发展水平不高的国家。（3）根据各地区的比较优势，亚洲国家适合效率寻求型和市场寻求型的企业投资，欧洲和美洲国家适合资源寻求型和战略资产寻求型的企业投资，非洲国家适合资源寻求型、效率寻求型和市场寻求型的企业投资。［结论］中国农业企业应结合企业投资目标和各地区的比较优势，合理选择投资区位，适时转变投资策略与模式，积极防范海外耕地投资过程中的自然风险、政治环境风险和道德风险等，以提高投资效果。     

Do satisfying walking and cycling trips result in more future trips with active travel modes? An exploratory study

Previous studies have indicated that travel satisfaction - the experienced emotions during, and cognitive evaluation of, a trip - can be affected by travel mode choice and other trip characteristics. However, as satisfactory trips might improve a person's attitude towards the used mode, persons may be more likely to use that same mode for future trips of the same kind. Hence, a cyclical process between travel mode choice and travel satisfaction might occur. In this paper we begin to analyse this process—using a structural equation modelling approach on cross-sectional data—for people who engage in walking and cycling for leisure trips in the Belgian city of Ghent. The focus on walking and cycling reflects recent studies indicating that active travel is often associated with the highest levels of travel satisfaction. Results of this exploratory analysis offer tentative support for the idea of a cyclical process: the evaluation of walking and cycling trips positively affects the respondents' attitude towards the respective mode, which in turn has a positive effect on choosing that mode.     

Improving spatial accessibility to regional health systems through facility capacity management

In austerity times, the general interest to reduce costs and improve efficiency levels often resulted into local cuts to public expenditure and profound reorganizations of existing service networks, especially in sectors like healthcare. In Italy, a recent reform prescribed the reconfiguration of time-dependent (i.e. emergency) hospital networks with the aim of improving patients’ accessibility conditions. In order to evaluate the impacts determined by this reorganization, we perform a spatial analysis in which we consider the distance from the closest facility as an accessibility measure. Results obtained from the spatial analysis confirm that users effectively benefit from the reorganization process but also that further improvements are possible, especially for the worst served ones. To this end, we also propose solving a mathematical programming model aiming at redistributing the capacities, i.e. the supply of beds, among the hospitals of the network seeking to maximize users’ accessibility. The realized computational experiments show that averagely better and even more equitable accessibility conditions could be obtained by containing the deriving reorganization costs.     

大数据背景下区域木材物流配送中心选址

指出了我国木材物流存在的主要问题以及解决方案,结合大数据技术,利用遗传算法进行木材物流配送中心的选址,建立了数学模型并进行了案例分析,以达到对木材物流成本和服务的优化。