区域产业发展视角的农业综合开发影响评估——基于对蔬菜产业的干预效应分析

【目的】通过定量方法准确评估农业综合开发对区域优势产业发展的影响有重要意义。【方法】从农业综合开发对蔬菜产业的项目干预效应入手,以县级为单位,将当年农业综合开发项目扶持内容包括蔬菜产业的县级单位划分为干预组,其他为控制组。采用可以有效解决样品选择偏差的倾向得分匹配方法,通过引入协变量、平衡检验、匹配等步骤,在控制组中找到与干预组成员单位特征相似的成员,构建反事实研究框架。【结果】结果得出,项目干预组比控制组区域的蔬菜播种面积占比高出1~3个百分点,说明农业综合开发项目对蔬菜产业的扶持对蔬菜播种面积的扩大有促进作用,利于蔬菜产业壮大。通过协变量影响力分析得出,地区的蔬菜生产优势是最重要的影响因素,从侧面证明了农业综合开发项目的扶持方向紧跟区域优势的政策宗旨。【结论】可见,通过有方向性的农业综合开发项目实施扶持特定产业对促进区域优势产业发展和实现农业结构优化是有效的。     

The substitutes condition and the lattice structure of the set of stable allocations

In the many-to-one matching model with contracts, I show that there is no restriction on preferences weaker than substitutable preferences which guarantees that the set of stable allocations is a lattice. Thus, when contracts are not substitutes, removing agents from the economy may decrease the payoffs to existing agents on both sides of the market.     

基于作业过程的园林绿化项目资源清单模型

结合生产要素六元理论，对园林绿化项目资源进行界定；以作业过程为信息关联节点，通过施工工序分解和资源特征匹配，构造园林绿化项目的“产出-作业”分配关系描述矩阵和“作业-资源”消耗关系描述矩阵。XX科技园林绿化企业的应用结果表明，项目资源清单模型解决了目前园林绿化企业资源信息分离使用的现状，是企业快速构建项目资源计划表、项目施工方案以及快速估算项目成本等的基础数据信息。     

战略性新兴产业集群创新网络形成机制研究——基于灰靶双边匹配的决策方法

战略性新兴产业的发展对国民经济和社会发展具有重要的战略意义，目前中国战略性新兴产业仍面临着“高端产业，低端技术”的发展困境，如何突破产业关键技术促进产业健康、可持续发展已成为亟待解决的问题。战略性新兴产业集群创新网络的形成是突破产业关键技术、共性技术及前瞻性技术的核心环节，中国正在兴起的产业技术研究院、航空高技术产业园等跨组织知识集成平台为培育和发展战略性新兴产业集群创新网络提供了重要的支撑平台。本文依托跨组织知识集成平台探究了战略性新兴产业集群创新网络的形成机制，构建了创新主体间的灰靶双边匹配模型，并采用平衡计分法建立了以创新能力为重要衡量标准的综合评价指标体系，最后通过案例进行了分析，证明了其有效性和实用性，可为促进战略性新兴产业集群创新网络的形成提供理论指导。     

Are EU trade preferences really effective? An impact evaluation assessment of the Southern Mediterranean Countries’ case

This work assesses the causal impact of the EU trade preferences granted to the Southern Mediterranean Countries (SMCs) in agriculture and fishery products over the period 2004–2014. It overcomes some of the weaknesses of previous assessments and presents several methodological improvements. Firstly, it relies on a continuous treatment – i.e. preferential margins – to capture the ‘average treatment effect’ of trade preferences, rather than on a binary treatment based on dummy variables. Secondly, it uses highly disaggregated data at sectoral level in order to evaluate properly the preferential treatment. Thirdly, it applies a non-parametric matching technique for continuous treatment – specifically, a generalized propensity score matching. The results show, on the one hand, that the impact of the EU preferences is positive and significant on SMCs trade and is better evaluated using impact evaluation techniques. On the other hand, they demonstrate that the relationship between preferences and trade flows is asymmetric and warn against the risk of providing too much of a good thing. These results raise important issues for policy-making. First, they demonstrate that raising the level of preferences is not the solution to foster the SMCs trade towards EU. Second, that the policy-makers should put more emphasis on complementary factors other than trade barriers.     

The effects of exports on facility environmental performance: Evidence from a matching approach

This paper employs matching techniques to investigate the effects of facility export status on environmental performance. Using facility-level criteria air emission data in the US manufacturing industry, we find the industry-specific effects of export status on emission intensity, measured by emissions per value of sale. In some industries, there is consistent and robust evidence supporting the superior environmental performance of exporters relative to non-exporters in terms of emission intensity for all criteria air pollutants tracked. In other industries, we find weak evidence that exporters appear to have a higher emission intensity than non-exporters. This industrial heterogeneity in the effects of exporting on the environment is closely related to industrial characteristics including pollution abatement capital expenditure, trade costs, capital intensity and others.     

市外旅行商行为与重庆旅游地营销匹配度探讨——基于网络调查视角

旅行商是连接旅游者和旅游地的桥梁。虽然旅行商与旅游地之间形成密不可分的利益关系,但在现实的旅行商和旅游地关系中,却存在较多的问题:个别大型旅行商"绑架"要挟旅游地,旅游地营销战略与旅行商推荐线路性质不匹配等。以压力-状态-响应理论和刺激-反映理论为指导,选取2010年和2011年国家旅游局发布的100强上榜旅行商中的重庆旅游地以外的60家旅行商为样本,通过网络调查方法,获取其推介的重庆旅游线路的相关情况,并加以分析整理,再结合重庆市旅游营销的具体实践,探求二者之间的匹配响应关系,得出市外旅行商和重庆旅游地营销之间存在匹配响应较低的结论,其结果是大大降低重庆旅游营销效果。最后,文章给出旅游地和旅行商之间匹配关系调整的一些对策,以期对重庆旅游营销有所裨益。     

Impact of contracts in high yielding varieties seed production on profits and yield: The case of Nepal

Nepal’s population continues to grow, but the agricultural sector’s performance remains almost stagnant. This has led to a decline in the per capita availability of food. Increasing agricultural productivity is the key to agricultural growth, and one strategy for increasing agricultural productivity is to use improved seeds. This study investigates the impact of contract farming (CF) in high yielding varieties (HYV) of paddy seed production on costs, yield, and profits of smallholder farms in Nepal. Using farm-level data and a non-parametric propensity score matching estimator, the study finds a significant positive impact of contract HYV seed farming on revenues, profits, and yield, and a significant negative impact on total costs of production. Additionally, very small farms (⩽0.43 ha) with CF in HYV paddy seeds tend to gain the most when it comes to yield per hectare. Our estimates reveal that the average smallholder household in Nepal engaged in CF with input conditions receives higher profits. However, farmers engaged in CF with output conditions tend to have higher yields but smaller profits. Finally, farmers engaged in CF in HYV paddy seeds with both input and output conditions have the highest yield gains and significantly higher profits.     

Exploring the mismatch between credit ratings and loss-given-default: A credit risk approach

It is commonly observed that high grade loans with better ratings are often associated with low recoveries if they default (i.e. with relatively high loss-given-default (LGD)). To address the mismatch problem, this paper proposes a credit risk approach by minimizing LGD for higher rated loans as a risk-rating matching standard in the sense that the decreasing LGD from creditors’ perspective is associated with higher credit rating for the borrower. This standard forces customers’ credit rating of each grade to be optimally determined in correspondence to its LGD, which means the LGD of high grade loans tends to be low. The approach is then tested using three credit datasets from China, i.e. credit data from 2044 farmers, 2157 small private businesses and 3111 SMEs. The empirical results show that the proposed approach indeed guides the way to solve the mismatch phenomenon between credit ratings and LGDs in the existing credit rating literature. By optimally determining credit ratings, the findings derived from this paper help provide a valuable reference for bankers, and bond investors to manage their credit risk.     

基于供应链的物流企业战略匹配能力研究

文中通过回顾之前对物流能力所作的研究及相关理论背景的基础上，认为物流企业战略匹配能力是企业物流能力的一个重要方面，并做了简单的探讨分析，丰富了对物流企业能力的研究。