鲤科鱼类池塘养殖技术效率的研究

本文应用随机边界产量函数对我国鲤科鱼类池塘养殖的技术效率进行了分析。通过对全国7个省283个渔场的鲤科鱼类池塘养殖生产情况的分析，表明我国鲤科鱼类池塘养殖总体技术效率水平较高，平均技术效率水平达到70．8％。本文还对影响技术效率的主要因子进行了分析，并就如何进一步提高我国水产养殖生产的技术效率进行了探讨。     

Levelling the playing field for European Union agriculture: Does the Common Agricultural Policy impact homogeneously on farm productivity and efficiency?

Originally conceived as a post-war policy vehicle for ensuring agricultural self-sufficiency, the Common Agricultural Policy (CAP) has evolved into a multifunctional instrument designed to satisfy a diverse portfolio of European Union (EU) policy objectives including nature protection. Notwithstanding, whilst the CAP has become more environmental and socially responsible, it is still expected to deliver an efficient farm production system capable of competing on world markets. The current paper combines a farm business panel dataset for 98 EU territories with a Stochastic Frontier Analysis (SFA) approach, to assess the impact of four contemporary broad categories of CAP subsidy programs on efficiency and environmental sustainability. In accordance with the literature, this study more correctly defines inputs as “facilitating”, whilst following recent methodological developments, crop-subsidies are treated as an endogenous strategic variable in the production function. Comparing between two discrete time periods, further tests are conducted to examine the hypothesis of technical efficiency convergence across european territories. The results suggest that first pillar crop subsidies and pillar two environmental programs generate a disincentive effect on productivity, whilst in general, the CAP promotes technical efficiency convergence within Europe.     

中国大宗淡水鱼养殖户技术效率、TFP增长及分解——基于25个省份微观调查数据

本文基于2011—2017年养殖户的微观调查数据,利用超越对数的随机前沿生产函数实证分析了大宗淡水鱼养殖户的技术效率、TFP增长及其分解。研究发现,(1)大宗淡水鱼养殖户的技术效率为0.827,表明养殖户的技术利用水平还存在较大的改进空间;(2)不同养殖规模对养殖户技术效率影响不显著,但专业化养殖对技术效率具有显著的正向影响;(3)养殖户TFP年均增长率为3.29%,且呈持续增长趋势;(4)养殖户TFP增长主要来源于技术进步,但技术效率的下降阻碍了TFP的增长;(5)技术效率和TFP增长都具有明显的区域性特征,总体表现为从西部到东部递减的趋势。     

Small U.S. dairy farms: can they compete?

The U.S. dairy industry is undergoing rapid structural change, evolving from a structure including many small farmers in the Upper Midwest and Northeast to one that includes very large farms in new production regions. Small farms are struggling to retain competitiveness via improved management and low‐input systems. Using data from USDA's Agricultural Resource Management Survey, we determine the extent of U.S. conventional and pasture‐based milk production during 2003–2007, and estimate net returns, scale efficiency, and technical efficiency associated with the systems across different operation sizes. We compare the financial performance of small conventional and pasture‐based producers with one another and with large‐scale producers. A stochastic production frontier is used to analyze performance over the period for conventional and pasture technologies identified using a binomial logit model. Large conventional farms generally outperformed smaller farms using most economic measures—technical efficiency, various profitability measures, and returns to scale.     

Excess Capacity and Asymmetric Information in Developing Country Fisheries: The Malaysian Purse Seine Fishery

Excess capacity poses a problem in many developing country fisheries. These countries often pursue a development strategy aimed at expanding capacity under open access. Sustainable development, however, requires management. Principal-agent issues from asymmetric information between the regulator and fishers, which potentially form serious obstacles to fisheries management, arise in the likely forms of management. This article discusses principal-agent issues and examines the principal-agent moral hazard issue, which is due to divorce of ownership and vessel operations. The article also illustrates a method for estimating capacity when information is limited. The Peninsular Malaysian purse seine fishery forms a case study.     

Diversification economies and specialisation efficiencies in a mixed food and coffee smallholder farming system in Papua New Guinea

Smallholder farming systems in Papua New Guinea are characterised by an integrated set of cash cropping and subsistence food cropping activities. In the Highlands provinces, the subsistence food crop sub-system is dominated by sweet potato production. Coffee dominates the cash cropping sub-system, but a limited number of food crops are also grown for cash sale. The dynamics between sub-systems can influence the scope for complementarity between, and technical efficiency of, their operations, especially in light of the seasonality of demand for household labour and management inputs within the farming system. A crucial element of these dynamic processes is diversification into commercial agricultural production, which can influence factor productivity and the efficiency of crop production where smallholders maintain a strong production base in subsistence foods.
In this study we use survey data from households engaged in coffee and food crop production in the Benabena district of Eastern Highlands Province to derive technical efficiency indices for each household over two years. A stochastic input distance function approach is used to establish whether diversification economies exist and whether specialisation in coffee, subsistence food or cash food production significantly influences technical efficiency on the sampled smallholdings.
Diversification economies are weakly evident between subsistence food production and both coffee and cash food production, but diseconomies of diversification are discerned between coffee and cash food production. A number of factors are tested for their effects on technical efficiency. Significant technical efficiency gains are made from diversification among broad cropping enterprises.     

A short-run Johansen industry model for common-pool resources: planning a fishery's industrial capacity to curb overfishing

Current methods for assessing capacity and its utilisation infisheries operate at the firm-level, but neglect industry capacity.Here, we introduce the Johansen-Färe measure of plant capacityof the firm into a multi-output, frontier-based version of theshort-run Johansen industry model. The model determines firmcapacity utilisation such that current industry outputs aremaintained, while minimising the use of fixed inputs at industrylevel and assuming abundant variable inputs. Policy extensionsrelevant to combating overfishing include tightening quotas,seasonal closures, linking economic and plant capacity, decommissioningschemes and area closures, implementation issues and equityconsiderations. The application to the Danish fisheries revealssubstantial overcapacity in the Danish fleet.