环境污染治理成本内部化条件下的适度生猪养殖规模的研究

Optimum-scale of Pig Farming: A Perspective of Internalizing the Cost of Environmental Pollution Control

本文基于对江苏省阜宁县261个生猪养殖户的实地调查,从生猪养殖投入与产出的角度,考察了生猪养殖规模报酬情况。研究发现,考虑生猪养殖综合技术水平与资本、劳动力和土地等生产要素对生猪规模产量的影响,阜宁县生猪养殖存在规模报酬递减。由此,如果政府单纯出于提高生猪规模产量的目的,鼓励养殖户扩大养殖规模,满足猪肉市场需求的政策并不可取。研究还发现,当养殖户不承担相应的环境污染治理成本时,最佳的养殖规模在600-800头之间;当环境污染治理成本内部化时,最佳的养殖规模在31-35头之间。与此同时,生猪的市场价格与政府政策因素也影响最佳的生猪养殖规模。生猪的市场价格越高,则最佳养殖规模量越大;政府的目标函数不同,最佳养殖规模量也将随之改变。故政府应该根据生猪产业分工的区域发展目标,制定相应的政策策略,通过政策调节区域内不同层次的养殖主体的生猪养殖规模保持在一个合理的区间内,以实现经济效益与环境效益的统一。

Based on the investigation of 261 pig farmers from Funing Country, Jiangsu province, this paper examined the returns to scale in pig fanning from the perspective of input and output of pig farming. The results indicate that taking the effect of comprehensive technical level on pig farming, capital, labor and land into account, pig farming in Funing Country is at the decreasing stage of returns to scale. Thus, it is undesirable to encourage farmers to expand the scale of farming and then to meet the demand of pork market if the government is just from promoting pig output angle. We also found that, when pig farmers don＇ t bear the cost of environmental pollution control, the optimum-scale is between 600 herds and 800 herds; when pig farmers bear the whole cost of environmental pollution control, the optimum-scale is between 31 herds and 35 herds. Meanwhile, the price of pigs and government policy also affect optimum-scale. In a word, the price of pigs is higher; the optimum-scale is larger; the government＇ s objective function can change the optimum-scale. Therefore, in order to realize the unification of the economic and environmental benefits, the government should formulate the corresponding policies on the basis of the division of pig industry, and affect the scale of farming within a reasonable range through policies.