基于不同城市化发展阶段的山西省城镇建设用地适度集约利用研究

研究目的:针对城市化进程中的土地低效利用以及过度集约问题,探讨不同城市化发展阶段的土地集约利用状况及适度集约利用状态。研究方法:采用匹配度模型、曲线估计模型和多目标规划模型,对山西省的土地集约利用进行分区优化。研究结果:(1)1999—2012年山西省土地集约利用与城市化水平之间的匹配趋势逐渐由失调、磨合向协调转变,但不同地区之间的匹配水平差距却在逐渐扩大;(2)2018年山西省城市化水平处于低于30%、30%～70%和高于70%时,以单位城镇建设用地固定资产投资额为表征的土地适度集约利用值分别为249.93万元/km~2、367.57万元/km~2和692.72万元/km~2,两项指标叠加全省可划分为平稳发展区、重点挖潜区和优化拓展区,并提出了不同地区差别化的建设用地管控政策。研究结论:不同城市化发展阶段的土地适度集约利用研究能为制定区域差别化政策提供参考,以促进该地区的土地集约利用水平达到适度状态。     

“倒挂型”土地利用总体规划的耕地保护效果评价

研究目的:揭示"倒挂型"土地利用总体规划与耕地保护效果之间的关系,以期为国土空间规划的编制提供参考。研究方法:倾向值匹配法。研究结果:(1)耕地"倒挂型"规划对耕地面积净变化的影响具有统计显著性,2006—2008年,耕保指标"倒挂型"规划使耕地面积净变化量平均减少2.270万hm2;(2)2010—2016年,耕保指标"倒挂型"规划使耕地面积净变化量平均减少0.496万hm2;(3)建设用地"倒挂型"规划对耕地面积净变化量并无显著影响。研究结论:在省级政府耕地保护责任目标考核的制度环境下,耕地"倒挂型"规划对地方政府形成一定压力,促使各级政府采取措施加以应对,从而使得"倒挂型"规划在一定程度上降低了耕地净减少量。     

Collective livestock research for sustainable disease management in Mali and Burkina Faso

An international multi-disciplinary team of scientists, led by the International Livestock Research Institute (ILRI), tackled the problem of bovine trypanosomosis and the development of drug resistance in West Africa, inter alia, by the promotion of rational drug use (RDU) principles. These principles had been brought to farmers by practical training and by the provision of information leaflets. This study aimed to evaluate the impact of RDU training at smallholder level with respect to advances in farmers' knowledge and farm productivity before research outputs could be scaled up. Therefore, 508 cattle farmers attended a disease-specific knowledge test and provided information about farm production. Results show that farmers who participated in the training are more likely to identify signs and causes of the disease and to correctly administer drugs. Allocating scores to each question in the knowledge tests and scrutinizing the differences between trained and untrained farmers by matching procedures shows that participating farmers reach higher scores in all knowledge categories. Moreover, the acquisition of additional knowledge and the application of improved control strategies significantly increase farm performance. Additionally, an allocative effect was identified since trypanocide expenditures were saved by less expensive inputs.     

大功率压电换能器的阻抗匹配研究

本文从实际工作条件出发,讨论了大功率压电换能器的匹配问题。强调指出了换能器的等效阻R在分析换能器工作状况和匹配电路时的重要性,并从工程技术的角度对匹配电感的设计进行了分析,提出将效率作为衡量匹配电路的一个重要指标。     

新环保法实施增大了企业的技术创新投入吗？——基于PSM-DID方法的研究

以2012—2017年A股上市公司为样本,借助双重差分倾向得分匹配法（PSM-DID）研究了新环保法实施这一外生性事件对企业技术创新投入的影响。结果显示,新环保法实施后受影响企业的技术创新投入有所增加,但结果并不显著。进一步探究其原因,发现除新环保法影响可能存在的时滞性特征以外,企业并没有在新环保法实施环境下对企业的资本结构、治理结构和激励方案等影响企业技术创新的重大方面做出及时调整,导致环保法的强制性作用无法快速、有效地影响企业的技术创新。     

Testing the null hypothesis of no regime switching with an application to GDP growth rates

This paper presents tests for the null hypothesis of no regime switching in Hamilton’s (Econometrica 57:357–384, 1989) regime switching model. The test procedures exploit similarities between regime switching models, autoregressions with measurement errors, and finite mixture models. The proposed tests are computationally simple and, contrary to likelihood based tests, have a standard distribution under the null. When the methodology is applied to US GDP growth rates, no strong evidence of regime switching is found. I thank Don Andrews, Peter Phillips, Yuichi Kitamura, Anat Bracha, Patrik Guggenberger, Orit Whiteman and three anonymous referees for useful comments and suggestions.     

重庆市制造业的绿色经济增长核算：2001—2010

基于生产前沿理论的绿色经济增长核算模型,不仅将技术无效率和环境代价纳入了分析框架,而且还与“物质平衡思路”一致;该模型将绿色经济增长的源泉分解为环境约束下的技术进步、技术效率变化和资本深化3大部分.对重庆市27个制造行业的经验分析结论表明:经济增长中普遍存在着技术无效率现象,但50％以上行业的技术效率都得到了改善或维持不变;资本深化是经济增长的主要源泉,而技术进步主导的全要素生产率变动在其中的贡献相对较小;技术进步是引致全要素生产率增长的主要原因.为充分发挥重庆市制造业可持续发展潜力,后续发展中必须转变经济发展方式,在环境约束下走技术进步和技术效率改善的绿色全要素生产率增长之路.     

Entrepreneurial innovativeness and growth ambitions in thick vs. thin regional innovation systems

Research in economic geography has paid increasing attention to regional innovation systems (RISs) as a potential vehicle for growth and development. Yet despite an increasing amount of research studying RISs in particular and economic regions in general, we have limited knowledge about their influence on entrepreneurs and entrepreneurship. We respond to this knowledge gap and study if entrepreneurs’ localization in thick vs. thin RISs affects their innovativeness and growth ambitions. Thick RISs are predominately urbanized spaces that include organizations of higher-level education, R&D intensive milieus, and an ample industry sector, while thin RISs to a lesser degree encompass these features. Empirically, we analyse 870–917 entrepreneurial firms in Agder of Southern Norway. Based on trade and labour markets, as defined by the EU’s classification of local administrative units (LAU1), we identify two thick and six thin RISs in Agder. Econometric analyses show that entrepreneurs located in thick RISs are more innovative than entrepreneurs located in thin RISs, but there are no significant differences concerning entrepreneurs’ growth ambitions. In light of our findings, we discuss the potential agency role played by entrepreneurial firms at a micro level on path dependent features of RISs at a macro level.     

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。     

Local poverty reduction in Chile and Mexico: The role of food manufacturing growth

This paper analyzes the relationship between local poverty and food manufacturing growth in Chile and Mexico using propensity score matching, differences in differences and spatial econometrics methods. We focus on food manufacturing as a sector with a number of characteristics that make it potentially pro-poor, and whose incentives for spatial distribution may either strengthen or dampen its poverty reduction potential. The overall results indicate growth in food manufacturing employment contributes to local poverty reduction.