Measuring Farm and Market Level Economic Impacts of Improved Maize Production Technologies in Ethiopia: Evidence from Panel Data

While it is often recognised that agricultural technology adoption decisions are intertwined and best characterised by multivariate models, typical approaches to examining adoption and impacts of agricultural technology have focused on single technology adoption choice and ignored interdependence among technologies. We examine farm‐ and market‐level impacts of multiple technology adoption choices using comprehensive household survey data collected in 2010/11 and 2012/13 in Ethiopia. Economic surplus analysis combined with panel data switching endogenous regression models are used to compute the supply shift parameter (K‐shift parameter), while at the same time controlling for the endogeneity inherent in agricultural technology adoption among farmers. We find that our improved technology set choices have significant impacts on farm‐level maize yield and maize production costs, where the greatest effect appears to be generated when various technologies are combined. The change in maize yield and production costs results in an average 26.4% cost reduction per kilogram of maize output (the K‐shift parameter). This increases the producer and consumer surpluses by US$ 140 and US$ 105 million per annum, respectively. These changes in economic surplus help to reduce the number of poor people by an estimated 788 thousand per year. We conclude that deliberate extension efforts and other policies that encourage integration of technologies are important for maize technologies to yield their full potential at both farm and market levels.     

关于完全半解析函数的概念及性质的初步研究

给出完全半解析函数及其可调和的概念。讨论了线性性质及封闭性,研究了完全半解析函数的可调和性。得到了完全半解析函数的一些可调和条件,给出了完全半解析函数的构成。     

基于多源数据融合的地表覆盖数据重建研究进展综述

地表覆盖数据对于全球环境变化、生物多样性和发展政策制定有着重要意义。遥感已成为获取地表覆盖数据的重要手段。而目前的地表覆盖数据产品,如Globe Land30、FROM-GLC、MODIS Collection5、MODIS Cropland、Glob Cover、GLC2000等,存在数据精度不高、数据间一致性较差、与统计数据差异较大等问题。因此,基于多源数据融合的数据重建方法成为目前研究中的热点问题。文章检索了近10年关于多源数据融合在地表覆盖数据重建中的应用的相关文献,概括了多源数据在数据重建中的应用现状,并对基于多源数据融合的地表覆盖数据重建方法进行了归纳总结,重点评述了不同方法的特点及应用情况,阐明了各种方法的优势与不足,同时对存在的问题进行探讨并展望了未来基于多源数据融合的地表覆盖数据重建研究的发展方向。基于多源数据融合的数据重建方法包括基于多源遥感数据融合法以及基于多源遥感和非遥感数据融合法。该文在对基于多源遥感数据融合的数据重建方法进行论述时,主要讨论了其中应用最广泛的两种融合方法:基于数据一致性的融合法和基于回归分析的融合法。对于其他基于多源遥感数据融合的数据重建方法,如基于D-S证据理论融合法、基于数据集成融合法、基于统计模型融合法,也列举了最具代表性的相关文献进行论述。在对基于遥感数据和非遥感数据融合的数据重建方法进行论述时,主要讨论了其3种空间分配方法:完全依赖法、部分依赖法、动态依赖法。在对目前研究进行探讨的过程中,该文对其研究区域、数据源、地表覆盖类型、空间分辨率、融合方法和文献来源进行总结分析,并重点就融合方法展开讨论。围绕各种融合方法在数据重建中的运用,该文归纳出目前研究中存在的主要问题:研究对象和区域上的不足,研究区多为全球及欧美,其他区域的研究过少,研究对象多为所有地表覆盖类型和森林,对耕地和草地的研究过少;融合算法上的不足、重建结果精度上的不足。最后,指出基于多源数据融合的数据重建方法未来的发展方向,即综合运用两类方法,得到具有详细完整空间信息的长时间序列的地表覆盖数据集。     

“主体-技术”协同视角下的战略性新兴产业创新网络分类研究——以新能源汽车产业为例

本文以“主体-技术”协同视角来分析战略性新兴产业创新网络形成的内在机理和分类模式。在结合2-模网络理论基础上,从核心技术和创新主体两个维度出发,将战略性新兴产业创新网络分为单核心实验室型、单核心产业链型、单核心辅助型、单核心复合型、多核心实验室型、多核心产业链型、多核心辅助型和多核心复合型。同时,以中国新能源汽车产业为例,通过实证分析发现：除了单核心辅助型和多核心辅助型之外,其它6种模式均存在,并进一步对其创新网络的分类模式及相关特征进行了全面分析。     

TAX‐LIMITED REACTION FUNCTIONS

This paper models for the first time a spatial process in local tax policies in the presence of centrally imposed fiscal limitations. Focusing on the frequently encountered case of a tax rate cap, we evaluate three empirical approaches to the analysis of spatially dependent limited tax policies: (i) a Bayesian spatial approach for censored dependent variables; (ii) a Tobit corner solution model augmented with a spatial lag; (iii) a spatial discrete hazard model. The evidence arising from an investigation of severely state‐constrained local vehicle taxes in Italy suggests that ignoring tax limitations can lead to substantial underestimation of inter‐jurisdictional fiscal interaction. Copyright © 2011 John Wiley & Sons, Ltd.     

Lobbying for Education in a Two‐Sector Model

Firms specialized in two different sectors lobby to induce the government to subsidize the type of education complementary to their production. Lobbying is endogenous. We show that, if lobbying is not costly, both sectors will lobby in equilibrium and the education policy will induce the same skill composition that would be chosen by the social planner. However, if lobbying is costly and there is sufficient asymmetry between the sectors, only one sector will exert pressure on the policy‐maker in the attempt to direct resources toward the type of education required by its production. Which sector will engage in lobbying depends on relative size, productivity, and price. We also provide some preliminary evidence that lobbying activity by firms may influence the production of skills needed by those firms.     

The Italian airport industry in transition: a performance analysis

This paper analyzes the impacts of Italian government actions on the efficiency of 36 airports between 2001 and 2003. The changes have included privatization, enlargement of the services provided directly by airport management companies, through the modification of the concession agreements, and the creation of two hubs. The analysis, using the consolidated two-stage data envelopment analysis with bootstrapping, indicates that airports with a majority public holding are on average more efficient and the presence of two hubs is source of inefficiency.     

递延所得税项目、条件稳健性与非条件稳健性

以所得税会计准则的执行以及企业所得税改革为背景,从条件稳健性与非条件稳健性两方面考察了中国上市公司2007～2010年递延所得税项目对会计稳健性的影响,证明了递延所得税资产和递延所得税收益(费用)既导致了非条件稳健性,又导致了条件稳健性；而递延所得税负债引起了条件稳健性,在非条件稳健性方面,不但没有表现出稳健性,反而表现出一定的激进性,说明企业在对递延所得税负债的确认上,不但没有高估负债,反而可能低估负债.     

韩国高速铁路投融资体制和运营管理模式

研究韩国高速铁路投融资模式和运营管理模式,系统总结韩国高速铁路建设发展的特点和经验。韩国是通过引进国外先进技术并进行再创新的途径发展高速铁路,深入研究韩国高铁建设运营的实践经验,对于推动我国铁路现代化建设、实现高速铁路可持续发展具有重要的参考价值。     

Renminbi＇s Potential to Become a Global Currency

This paper is a tentative endeavor to delineate the potential of the renminbi to become a global currency. It first analyzes the critical economic, financial and policy attributes that are required to support a currency to gain an international role. It then examines whether China has the potential to acquire these attributes. The paper concludes by offering some provisional observations on the implications for Asia and the global economy, should the renminbi evolve into a world currency in the coming decades.