中文摘要：

本文总结了前人对农地城市流转外部成本的研究,在分析了已有文献存在问题的基础上提出农地流转外部性的内部化应在内、外部边界划分的基础上进行。结合过去的研究,将外部成本效应归并为治安状况变差、空气质量下降、噪音污染、自然景观的破坏、公共设施不足、垃圾堆积、农地产量下降7个方面。实证研究选取仙桃市近郊区4个代表性的农地流转地块作为研究样本,通过问卷调查,应用CVM、AHP等方法测算和分解了其农地流转外部成本,得到结果分别为0.6×10^4元（/hm^2·a）、1.45×10^4元（/hm^2·a）、1.17×10^4元/（hm^2·a）和1.15×10^4元/（hm^2·a）;研究表明个体受农地流转外部性影响的大小主要和性别、年龄、受教育程度、政治面貌、家庭成员数量、家庭月收入等因素相关;而农地流转的外部成本大小受到区域繁华程度、土地利用类型、个体偏好等因素的影响。

英文摘要：

The contradiction between occupying farmland for non-agricultural construction and farmland preservation receive increasing attentions in recent years.Measurement of benefits-cost in rural-urban land conversion processes would benefit policy-making.This paper aims to examine the measurement of external costs in rural-urban land.First,an extensive and comprehensive review on this topic was performed,indicating that previous studies generally fall short of： 1） without considering the externality systematically;2） confusions between the externality and non-market value;and 3） a vague definition on the boundary of external and internal parts.To address such problems,the paper defines the external costs in rural-urban land conversion,in which the land conversion external costs should be considered together with land conversion external benefits,external costs and benefits of farmland preservation,as separate 4 parts of total land conversion externality.Meanwhile,the concept of external costs should be distinguished from the non-market value.After that,the authors divided the external parts and internal parts by homogeneity areas,and separated affected areas and unaffected areas by the Loomis’ equation which is used in range estimation of public goods.The effects of external costs were generalized as 7 parts： worsening crime,deterioration of air quality,noise pollution,landscape broken,inadequacy of public facilities,accumulation of refuse and decline of farmland production.As an empirical study,data were from questionnaire surveys conducted in the urban fringe of Xiantao City,where land conversion was accelerated obviously because of being at a preliminary development phase.The willingness to pay avoiding external costs was measured with the contingent value method and oral presentation method.Then,based on the additivity assumption underlying utility functions,the total value was decomposed by the Analytic Hierarchy Process （AHP） method.Results showed that the land conversion external costs were 0.6×