中国东海、黄海及南海捕捞能力的比较分析

以《中国渔业统计年鉴》中2009~2014年东海、黄海、南海的海洋捕捞渔船数、总功率、总吨位作为不变投入,专业劳动力作为可变投入,海洋捕捞产量为产出,使用数据包络分析法(data envelopment analysis,DEA)对捕捞能力利用度以及理想投入进行分析,总结2009~2014年各海域的规模效率和纯技术效率,计算无偏能力利用度,评价投入配置的合理性以及各生产投入因素对能力利用度的影响。结果表明:黄海海域捕捞纯技术效率较高,但能力利用度受资源衰退的影响明显,并有下降趋势,存在大比例的生产浪费,生产规模亟需优化;东海海域能力利用度和纯技术效率都呈稳定增长趋势,近年对生产投入的控制有一定成效,可变投入配置比例也较合理;南海海域能力利用度和技术效率趋势与东海海域相同,但减船转产实施的不明显,生产投入还有一定的缩减空间。     

基于DEA超效率模型的种业上市公司营销效率研究

种业上市公司营销效率代表着我国种业营销的最好水平,分析种业上市公司的营销效率能反映当前我国种业的整体营销效率的现状。文章运用DEA超效率模型对种业上市公司2004～2008年的数据进行了实证研究。结果显示,现阶段我国种业营销效率整体水平较低,大多数公司处于DEA中度或者严重无效的状况,前景不容乐观。各级政府和农业相关部门要采取积极的应对措施。     

水产技术推广资源配置效率及其区域差异分析

渔业在我国国民经济中占有重要地位和作用,水产技术推广体系是保证我国渔业持续健康发展的基础。本文采用数据包络分析(data envelopment analysis,DEA)中的BCC模型分析2013—2015年全国各地区的水产技术推广资源配置效率,以探究我国各地区水产技术推广资源配置效率的差异。结果表明,我国水产技术推广资源整体配置效率不高,区域间的配置效率差异明显,中南地区水产技术推广资源配置综合效率、纯技术效率和规模效率都高于全国平均水平,东北地区低于全国平均水平。建议通过增加水产技术推广资源总量、因地制宜的配置水产技术推广资源、建立水产技术推广体系联合协作工作机制等方法来提高水产资源配置效率。     

技术效率、技术进步与我国羊绒生产的全要素生产率——基于DEA—Malmquist指数法的分析

根据2003～2009年内蒙古、宁夏和西藏的羊绒生产成本收益面板数据,本文利用DEA—Malmquist指数法,对我国羊绒生产的全要素生产率（TFP）进行了测算和分析。研究结果表明,我国羊绒生产TFP年均增长率为负且总体上呈现“N”状的变化特征;羊绒生产出现了技术效率提高与技术退化并存的现象,羊绒生产TFP的增长主要来源于技术效率的提高,但这种作用不强,技术退化则对TFP的增长形成了较强的负向作用;宁夏和西藏羊绒生产TFP均出现不同程度的下降,只有内蒙古实现了增长。最后,本文提出了相应的政策建议。     

通过调整产出量提高螺杆压缩机的效率

<正> 螺杆压缩机的优点之一是能够平稳地调整其产出量。最常见的调整办法是借助一个可移动的滑阀装置,当它移动时,就可在压缩过程开始的瞬间改变蒸汽腔的容积。 圣·彼得堡制冷工业技术学院制冷机教研室曾进行过实验性螺杆压缩机的研究,目的在于确定其在调整产出量时的效率。 实验性压缩机的主要技术特性:理论容     

中国淡水养殖技术效率研究——基于2018年的数据

根据2018年中国淡水养殖地区统计数据,分析2018年中国淡水养殖技术效率水平。通过构建DEA模型,测算不同地区淡水养殖的效率值。结果表明:2018年中国整体淡水养殖技术效率较高,为0.85;不同地区的技术效率水平值存在差异,最高值为1.00,最低值为0.76。从空间分布看,7个区域的技术效率值不同,但没有明显区别,因此认为技术效率与空间分布无明显关系。基于研究结果,从技术创新、交流合作、产业结构等方面提出了相关建议,以期为中国淡水养殖效率研究提供可参考的资料。     

农村金融发展与城乡收入差距实证研究——基于广东省1978～2008年数据

本文基于广东省1978～2008年数据,运用数理方法以及对农村金融发展与收入差距关系进行实证研究发现：农村金融发展与城乡收入差距具有长期稳定均衡关系。从长期来看,有效发展农村金融会缩小广东省城乡收入差距,农村金融的发展规模和效率对收入差距比具有显著负效应;而短期内,提升农村金融发展效率显著缩小收入差距,但农村金融发展规模的作用不显著。     

提高母猪繁殖效率的关键技术

<正>母猪的繁殖效率是衡量规模化猪场经济效益的重要指标。据统计,2009年全国平均1头母猪年产健壮活仔仅13.8头,严重影响我国养猪的生产效益。在低碳经济背景下,如何提高母猪的生产效率显得尤为重要。国内外成功的经验证明,对母猪进行科学有效的繁殖调控措施,可达到提高繁殖效率和总体生产效率的目的。母猪的繁殖调控是指通过各种技术和管理手段,人为地调节和控制猪的繁殖过程或繁殖过程的某些环节,从而提高母猪的年生产力。规模猪场必须精确控制影响母猪繁殖的各个环节,如母猪     

中国农业用水效率区域差异与空间交互机理研究

基于2005-2019年中国31省份面板数据，采用超效率SBM模型和全要素用水效率指标，测度中国农业用水效率。并利用向量自回归模型（VAR），探究中国省域间农业用水效率的交互作用和溢出效应。结果表明：中国农业用水效率总体偏低， 2019年为0.690，存在31%的提升空间。农业用水综合效率与纯技术效率、规模效率呈正相关，但省份之间相关程度存在差异。西藏自治区纯技术效率最高，为1.022，山西省规模效率最高，为0.995。研究期内，中国农业用水效率均值集聚特征不显著，浙江、西藏和海南等三省（区）处于孤岛状态。中国农业用水效率呈西高东低，北高南低总体分布态势。VAR脉冲分析显示中国农业用水效率存在正向空间交互作用，其中以东部地区对中西部影响最为显著。要提高中国农业用水效率，一方面要重视农业科技创新，提高农业用水纯技术效率；另一方面要加强区域协作，充分发挥高效率用水区域的溢出效应     

罗非鱼生产技术效率与市场竞争力的关系分析

我国罗非鱼产量不断增长,但出口利润却一直在下降,市场竞争力不断下降,提升其市场竞争力的关键在于提高罗非鱼的生产技术效率。本文探讨了技术效率对市场竞争力的影响机理,同时通过国家罗非鱼产业技术体系示范县跟踪点养殖户的调研数据,利用随机前沿生产模型(SFA)对罗非鱼生产技术效率进行测算,统计分析了罗非鱼生产技术效率与其市场竞争力的关系,证实了技术效率是市场竞争力的重要影响因素,并指出提高技术效率是扭转罗非鱼市场竞争力下滑的关键。     

RESOURCE ALLOCATION EFFICIENCY OF THE PRAWN-CARP FARMERS OF BANGLADESH

This paper evaluates resource allocation efficiency of prawn-carp polyculture systems by making use of the data of 105 farmers of Bangladesh. Data Envelopment Analysis (DEA) was employed to estimate the efficiency. Mean technical efficiency (TE), allocative efficiency (AE) and cost efficiency (CE) were 85%, 58%, and 49%, respectively. Fifty percent of prawn-carp farmers displayed full TE whereas only 9% were cost efficient. Actual input application largely deviated from the technical and cost-efficient levels. TEs and AEs showed a positive and negative correlation with pond size, respectively. Labor, fingerlings and feed were overused while organic and inorganic fertilizers were underused in general. Adjustments in actual input allocations were necessary to make use consistent with TE and CE levels. The study concludes that mere achievement of technical efficiency in prawn-carp production may be a short-run concern; the farmers have to be economically efficient in the long-run.     

A REVIEW OF PRODUCTION FRONTIER RESEARCH IN AQUACULTURE (2001–2011)

Most research works on the production frontier in aquaculture focus on efficiency measurement using either Stochastic Production Frontier (SPF) or Data Envelopment Analysis (DEA). The studies on productivity growth in aquaculture were limited, perhaps due to lack of time-series data. Nevertheless, total factor productivity analysis (TFP) in fish farms has started gaining popularity in recent years. In addition, the majority of the efficiency studies have centered on technical efficiency analysis but substantial increases in the output levels can be fully realized through improving overall economic efficiency. Therefore, this review suggests that future research should estimate all three efficiency indices (i.e., technical, allocative and economic efficiencies).     

Economic efficiency of small-scale tilapia farms in Guangxi,China

ABSTRACT

The economic efficiency of small-scale tilapia farms in Guangxi, China were analyzed by using Data Envelopment Analysis (DEA). The mean technical (under CRS and VRS), allocative, and economic efficiencies of small-scale tilapia farms were 0.89, 0.97, 0.71 and 0.68, respectively. Efficiency analysis revealed that inefficient farms would have needed to increase production output levels by 32% to perform as well as the best practice farms. The decomposition of the economic efficiency showed that allocative inefficiency was the primary cause of economic inefficiency. There were positive relationships between economic efficiency and age, culture mode and period through Tobit regression, while experience, family members, and technology support had negative effects on economic efficiency. Lower input levels of feed quantity may help to increase the tilapia farming economic efficiency.     

Impact of Climate Change on the Technical Efficiency of Striped Catfish,Pangasianodon hypophthalmus,Farming in the Mekong Delta,Vietnam

The technical efficiency of randomly sampled pangasius farms in the Mekong Delta of Vietnam was estimated using data envelopment analysis, and factors affecting technical and scale efficiency were examined with bootstrap truncated regression. The mean technical efficiency score assuming variable returns to scale was 0.84. The technical efficiency of downstream farmers was higher due to lower energy costs and stocking once a year. Most of the up‐ and midstream farms needed to pump water and stocked at least three times in 2 yr. Regression analysis showed a positive effect on technical efficiency of the farmers' education level and having experienced climate change impact through flooding or salinity intrusion in the past. Farms affected by salinity intrusion had a lower scale efficiency as they reduce stocking frequency and rate. In general, reducing fish mortality and the cost of inputs, increasing scale of operation, and being trained, using appropriate methods, in management strategies may improve technical efficiency.     

Technical Efficiency of Tank Culture Systems in Peninsular Malaysia: An Application of Data Envelopment Analysis

The demand for animal protein especially fish is growing rapidly perhaps due to rapid expansion of population, increased incomes, and changes in eating habits and life styles of consumers. Capture fisheries are currently overexploited and their yield has become stagnant over the last decades and, in some cases, has even declined. Nevertheless, aquaculture has the potential to meet these challenges if well practiced. The study therefore, aims to estimate Technical Efficiency of tank culture systems using Data Envelopment Analysis (DEA). Additionally, it also investigates the determinants of technical inefficiency by employing a regression model. The estimated technical efficiency was 0.89, which means that the fish farmers can reach full technical efficiency through reducing their input usage by another 11%. Results indicate that farmer’s experience, educational level, extension training, job status, and water management have positive and statistically significant impacts on technical efficiency. Therefore, increase in any of these factors will have a direct impact on technical efficiency.     

SOURCES OF PRODUCTIVITY GROWTH IN RAINBOW TROUT AQUACULTURE IN IRAN: TECHNICAL EFFICIENCY CHANGE OR TECHNOLOGICAL PROGRESS?

This study investigates the sources of total factor productivity (TFP) growth in rainbow trout production in Iran using data envelopment analysis (DEA). The Malmquist index is then employed to decompose the TFP growth into technical efficiency change and technological progress. We utilized panel data of 207 trout farms in the country over a 5-year period from 2003 to 2007. The results of this study revealed that TFP growth of rainbow trout farming has an increasing trend over the period at an average annual rate of 3.7%. The trend of cumulative technological change is negative and tends to be contrary to cumulative technical efficiency change. Although there is no technological change or innovation on trout farming, the technical efficiency change was found to be the sole source for TFP change, whereas the mean of technical efficiency was estimated to be about 66%. Therefore, there is still a great relative potential for increasing trout production through improvement in managerial efficiency as well as technological progress. The study suggests that Iran also has considerable room to enhance trout aquaculture's TFP growth by shifting the production frontier with adoption of new technologies and improving innovation.     

Economic efficiency and optimum stocking densities in fish polyculture: an application of data envelopment analysis (DEA) to Chinese fish farms

Polyculture is commonly practiced in pond aquaculture where several fish species are reared together, creating a multi-output production structure. This study applied a nonparametric data envelopment analysis (DEA) technique for multiple outputs to: (1) measure economic or ‘revenue' efficiency and its technical and allocative components for a sample of Chinese polyculture fish farms; and (2) derive the optimum stocking densities for different fish species. The mean economic efficiency was estimated to be 0.74. Technical inefficiencies accounted for most of the production inefficiencies in Chinese fish farms. On average, farmers should increase grass carp and decrease black carp stocking rates. Smaller farms and those from the developed regions were found to be relatively more technically and economically efficient.