市场容量、交易密度与农业服务规模决定

发展农业社会化服务市场,将农户卷入分工经济,是提高农业家庭经营效率的重要路径。已有研究较少关注农业社会化服务的生成机理。文章借助交易半径和交易密度的理论概念,一方面从服务商面临的交易半径选择、作业周期约束、交易费用等维度,刻画交易半径的决定机制;另一方面从信息传递和"赢定输移"策略等维度,考察农户卷入分工经济的需求约束。将服务商和农户的局限约束同时纳入模型分析发现：（1）农业社会化服务市场的初始交易密度,决定了服务商交易半径的增长速度;（2）当市场的信息披露程度和传递速度提高,"赢定输移"策略会促使小农卷入分工经济,并使得交易密度、交易半径和市场容量同时提升;（3）服务商的交易半径和市场容量受制于农业的时令特征和作业周期性,这为构建种植业"纬度布局"提供了理论依据。文章认为,中国农业现代化和组织化进程与农业分工经济和种植业布局调整密切关联。

Market Capacity,Transaction Density and the Decision of Agricultural Service Scale

Developing agricultural service market and households’ involvement in the division of labor are important ways to improve the effectiveness of households’ agricultural management, but the previous researches ignore the forming mechanism of agricultural social service. This paper employs the conceptions of transaction radius and transaction density to describe the decisive mechanism of transaction radius from the aspects of transaction radius choice, working cycle constraint, transaction cost facing households and analyzes the demand constraints of households’ involvement in division of labor from aspects of information transfer and the strategy of "winning keep and losing leave". And the constraints of service providers and farmers are also incorporated into the uniform model. The analytical results indicate that firstly the transaction density of the initial agricultural service market determines the growth rate of the transaction radius of the service provider. Secondly, with the development of the degree of information disclosure and delivery speed, the strategy of "winning keep and losing leave" will encourage small farmers to be involved in the division of labor, which increases transaction density, transaction radius and market capacity simultaneously. Thirdly, the transaction radius and market capacity of the service providers are subject to the seasonal characteristics and cyclical nature of the agriculture, which provides theoretical basis for the establishment of the "latitude layout" planting structure. The paper implies that the process of agricultural modernization and organization in China is closely related to the adjustment of the agricultural division of labor and the adjustment of the layout of the planting structure.