Knowledge diffusion and agricultural development

Low agricultural productivity remains the primary source of poverty in the developing regions and yet little is known about the influence on agricultural productivity of domestic and international accumulated R&D knowledge and the channels through which this knowledge is transmitted internationally. Following a large scientific literature, this article argues that R&D and R&D knowledge spillover are ecozone‐specific and, therefore, are transmitted internationally through ecozones, where ecozones are the broadest biogeographic division of the earth's land surface. Using data for a panel of 88 countries, it is shown that international knowledge spillovers are ecozone‐specific and have been an important contributing factor behind the marked widening of the income gap between developed and developing countries since 1983.     

粮食主产区耕地健康产能评价 ——以河南省温县为例

研究目的:探寻适合中国新时代耕地产能评价的新理论与方法,界定耕地健康产能内涵,构建评价指标体系,并应用河南省温县验证。研究方法:基于"需求—功能—维度—要素—指标"理论框架,构建耕地健康产能评价指标体系,运用综合算法、"1+X"累加模型法、图层叠加法定量评价耕地健康产能。研究结果:(1)温县耕地产能和耕地健康诊断结果地域分异特征明显,以青峰岭为界,北部耕地产能和健康状况较南部好;(2)耕地健康产能整体状况良好,乡镇间差异明显;(3)耕地健康产能结果更多取决于耕地健康诊断,主要受耕地生产环境和耕地系统弹性影响。研究结论:耕地健康产能评价指标体系和评价方法有应用性。     

基于碳排放的河南省粮食绿色全要素生产率分析及对策建议

［目的］为探索粮食绿色增产模式,推进农业供给侧结构性改革和绿色可持续发展。［方法］分别运用SBM-ML指数模型与DEA Malmquist指数模型对2004—2016年河南省粮食绿色全要素生产率和传统全要素生产率进行测算和对比分析,并采用ESDA法探讨了粮食绿色全要素生产率与粮食产出的空间关联性。［结果］河南省粮食绿色全要素生产率明显低于传统全要素生产率; 2004—2016年河南省粮食绿色全要素生产率的驱动因素经历了由技术进步驱动转变为技术效率驱动再转变为技术进步和技术效率共同驱动的过程,但技术进步的贡献率明显高于技术效率; 河南省粮食绿色全要素生产率与粮食产出的二元全局空间自相关大体呈“N”型变化,粮食绿色全要素生产率和粮食产出由不平衡发展逐渐趋向平衡发展。［结论］忽视碳排放的传统粮食全要素生产率测算与实际有较大偏差。建议通过转变发展模式,探索粮食绿色增产道路; 因地制宜,有效利用技术进步和技术效率双轮驱动; 不断推进河南省粮食绿色全要素生产率与粮食产出的平衡发展3项措施来实现粮食生产的综合提升。     

县域内耕地资源质量及其生产能力的相关性研究--以佛山市农用地分等为例

利用佛山市农用地分等的成果,通过对水田、旱地自然质量等指数和利用等指数与实际标准粮产量的相关性分析来研究县域内耕地自然质量、利用水平对耕地生产能力的影响.得出了耕地自然质量、利用水平对耕地生产能力的影响程度,发现两者对耕地生产能力的重要程度相当.     

A Question of Integrity: Variants of Bt Cotton,Pesticides and Productivity in Pakistan

Bt cotton remains one of the most widely grown biotech crops among smallholder farmers in lower income countries, and numerous studies attest to its advantages. However, the effectiveness of Bt toxin, which depends on many technical constraints, is heterogeneous. In Pakistan, the diffusion of Bt cotton occurred despite a weak regulatory system and without seed quality control; whether or not many varieties sold as Bt are in fact Bt is also questionable. We utilise nationally representative sample data to test the effects of Bt cotton use on productivity. Unlike previous studies, we invoke several indicators of Bt identity: variety name, official approval status, farmer belief, laboratory tests of Bt presence in plant tissue, and biophysical assays measuring Bt effectiveness. Only farmer belief affects cotton productivity in the standard production model, which does not treat Bt appropriately as damage‐abating. In the damage control framework, all Bt indicators reduce damage from pests. Biophysical indicators have the largest effect and official approval has the weakest. Findings have implications for impact measurement. For policy‐makers, they suggest the need, on ethical and productivity grounds, to improve variety information and monitor variety integrity closer to point of sale.     

Post-War Productivity Patterns in U.S. Agriculture: Influences of Aggregation Procedures in a State-Level Analysis

Annual data for forty-eight states are used to account for changes in the composition of input and output aggregates over space and time, and thereby to obtain new evidence on changes in inputs, outputs, and productivity in U.S. agriculture. The measures change significantly when we use state-specific rather than national prices and when we allow for changes in the composition of the aggregates, especially of labor and capital inputs. We compare our estimates and those reported by Ball et al. ( American Journal of Agricultural Economics 81(1999):164–79). The national estimates are similar but substantial differences are found in state-level productivity growth.     

我国海洋渔业第一产业劳动生产率的增长动力——基于转换份额分析法的实证分析

为研究我国海洋渔业第一产业劳动生产率增长的动力结构,运用转换份额分析法将1989-2014年我国海洋渔业第一产业劳动生产率增长率分解为由产业结构变迁引致的静态与动态结构变迁效应、由技术进步引致的生产率增长效应,结果显示生产率增长效应对海洋渔业第一产业劳动生产率的增长贡献远高于静态与动态结构变迁效应之和的贡献,静态与动态结构变迁效应之和的贡献表现为"先增大、后减少"态势,生产率增长效应的贡献表现为"先逐渐减少、后增大"态势。技术进步是海洋渔业第一产业劳动生产率增长的主要动力;海水养殖业对海洋渔业第一产业劳动生产率增长的贡献大于海洋捕捞业。     

中国地区工业部门二氧化碳排放量及碳排放约束下全要素生产率测算

估算了电力、热力的CO2折算系数,据此精确测算了1995—2008年中国29个省(自治区、直辖市)工业部门的CO2排放量,并运用方向性距离函数模型计算了考虑和不考虑CO2排放两种情形下各省区的工业TFP。结果显示:考虑CO2排放时中国工业部门的TFP增长率(碳效率)比不考虑CO2排放时高出2个百分点;东部地区的工业部门在两种情形下均是推动前沿技术进步的主要力量,且在考虑CO2排放情形下表现更为突出;2000年后,中部地区个别省份的工业部门开始进入技术前沿。结论表明:中国工业的可持续发展取得了显著成绩,其中东部地区的工业发展一直走在全国前列;虽然中、西部地区工业部门的技术追赶总体上相对缓慢,但近几年个别省份也在加快步伐;2003年后中国全要素CO2排放效率增长放缓甚至出现负增长。     

流动的现代性:国有单位职工流动性的统计描述

长期以来,计划与市场一直被视为单位社会变迁现代性内涵的重要解释变量,而日益增长的人口压力在其间的突出作用却鲜有触及。从社会人口学的视角,关注于国有单位职工的流动性,从时间、空间和动力三个维度探讨了人口压力与单位社会变迁紧密相关的现代性内涵。时间上,单位社会的现代性变迁呈现为倒U形,具有鲜明的"制度堕距"特征;空间上,单位社会的现代性变迁展现了人口蓄水池从乡村转移到城市的历程,具有东、中、西部同步即时效应与第一、二、三产业异时累积效应;无论时间维度,还是空间维度,都是一个"单位性依赖"的克服过程,其间既有市场导向"拉"的作用,更有政府主导的产业剥离"推"的作用。单位社会的变迁是现代性逻辑的必然结果,它的结构性作用仍将长期凸现。