新一轮退耕还林对农户收入影响的机理研究 ——基于赣南、鄂北农户调查的实证分析

研究目的：新一轮退耕还林补助资金即将到期之际,分析新一轮退耕还林对农户家庭收入的净效应并揭示其内在机制。研究方法：理论上阐述了新一轮退耕还林政策促进农户收入增长的作用机理,基于赣南、鄂北地区农户调查数据,利用倾向得分匹配法进行实证分析。研究结果：（1）无论是否包含退耕补贴,新一轮退耕还林政策对农户收入有正向影响;（2）退耕林种对农户收入的作用机理不同：种植经济林的农户增加了林果业收入和非农经营收入,减少了工资性收入;种植生态林的农户通过提高工资性收入,进而提高总收入水平。研究结论：新一轮退耕还林加快了农户生计转型的进程。政策实施5年后,农户形成与生态环境相适应且稳定的生产方式,为补偿政策的逐步退出创造有利条件,实现了新一轮退耕还林政策的造血功能。     

战略物流管理的效益模型

战略物流管理是新兴的现代管理技术 ,其中核心问题是如何提高效益。效益模型的策划和找出影响它的主要因素是本文所要解决的问题     

Strategy-proof Location on a Network

We consider rules that choose a location on a graph (e.g. a road network) based on agents' single-peaked preferences. First, we characterize the class of strategy-proof, onto rules when the graph is a tree. Such a rule is based on a collection of generalized median voter rules (Moulin, 1980) satisfying a consistency condition. Second, we characterize such rules for graphs containing cycles. We show that while such a rule is not necessarily dictatorial, the existence of a cycle grants some agent an amount of decisive power, unlike the case of trees. Rules for this case can be described in terms of a subclass of such rules for trees. Journal of Economic Literature Classification Numbers: C72, D78.     

Anticipated foreign military threat, arms accumulation, and the current account in a small open economy

This paper examines the effects of an anticipated foreign military threat on consumption, the home weapons stock, and net foreign asset position in a small open economy. If the utility function is separable between butter and guns, the economy decreases both butter and guns when the news arrives, accumulates foreign assets prior to the foreign threat realization, and increases guns as the foreign threat realizes. If the utility function is nonseparable between butter and guns, the economy may have two dynamic responses. The first is similar to the separable case, except that consumption exhibits a discrete jump when the foreign threat realizes. The second is that the economy increases both butter and guns on impact, decumulates foreign assets prior to the foreign threat implementation, but either increases or decreases guns as the foreign threat realizes.     

Descriptive statistics of large data sets by scatter plots, an exploratory approach

In the analysis of large tables of M variables on N observations one is interested in the relations between the variables and it is usual to inspect the M(M-1)/2 scatter plots of N points. Clearly, the scatter plot approach relies on visual inspection and is to be preferred in so far as applicable to detect simple relations, namely when M is small. Other approaches are needed for large values of M .
We consider that only the relatively few scatter plots that present a 'structure' are of interest for an exploratory analysis and, by 'structure', we mean a domain of specially high local density in the plot. Based on this concept, we propose a method constructed around two steps: the selection of the possibly interesting pairs of variables and the validation of the corresponding scatter plots. The selection of the pairs results from an algorithm based on a binary partitioning tree. The validation of the corresponding scatter plots enables the production of only those where a structure is found the recognition of a structure is derived from a statistic based on the length of the Minimum Spanning Tree constructed on the N points of the candidate scatter plot.
For illustration, we report on an industrial application where the method is routinely applied for exploratory purposes.     

林草结合 使林场成为新的畜牧基地

林业是国民经济的基础,这不是空泛的理论之争,而是如何进行经济建设及农业建设的实践之争。我国国土天然形成的大格局,决定了惟有实施林农牧共同发展的大农业战略,使山区、牧区、农区成三足鼎立之势,相互依持,共生共存,我国农业才有出路。这个大农业战略简称为"林草兴邦"。林草结合,也是国有林场建设的新思路。     

基于数据挖掘的电信客户信用分类模型研究

电信客户信用分析与预测,对于电信运营商在激烈竞争环境下,最大程度的在竞争活动中立于不败之地,具有重要意义。本文采用了SOM聚类算法和用传统经验对客户信用等级评分评级来确定信用等级类标号,再用决策树算法建立两个模型A和B。比较两个模型,选择性能较优者为最终模型并探讨了该模型的实际应用。     

基于余弦相似度(CS)和最小生成树(MST)的基金市场复杂网络研究

以中国基金市场中123家基金公司持有的投资组合为样本,综合运用余弦相似度(CS)和最小生成树(MST)方法,考量基金市场复杂网络。结果显示：各家基金公司持有股票组合的相似程度比持有债券组合的相似程度更高,表明他们持有的债券组合较之股票组合更加多元化,基金公司持有的股票相对集中于市值大、成长性高的公司。同时,全部资产投资组合、股票投资组合和债券投资组合等三类基金MST网络的节点度均服从幂律分布,表明大多数基金公司以少数强影响力基金公司为中心聚集起来,彼此之间具有较强的业务关联。此种网络结构特征可能导致市场风险向基金聚集团体集中,其抵御系统性风险的能力偏弱,也不利于满足投资者的理财多元化需求。     

The Language Backfire Effect: How Frontline Employees Decrease Customer Satisfaction through Language Use

Extant marketing research holds that customers prefer frontline personnel to speak the customers’ first language. Furthermore, current managerial practices instruct frontline employees to either use the customers’ first language or, in international settings, to use English. Through five studies in different retail and service contexts, we identify situations where the opposite is true. The results of the first two studies suggest that if customers initiate contact in a second language, the frontline employee’s switch to the customer’s first language constitutes an identity threat leading customers to feel less satisfied; an effect we term the language backfire effect. Our third study extends these results to a domestic context to test for the impact of linguistic acculturation on how immigrant customers perceive frontline employees’ language switch. The fourth study replicates the findings in a real-life retail context. These results present a paradox for marketing research: although frontline employees switch to customers’ first language to accommodate them, these actions might not have the desired consequences. Having identified and described the problem of the language backfire effect, our final study introduces and verifies a managerially actionable solution: combining the language switch with a language proficiency compliment offsets the language backfire effect.