基于双差分法的退耕还林工程对农户生计资本影响评价——以宁夏为例

Analysis of Effects of Sloping Land Conversion Program on Farmers' Livelihood Asset with Difference-in-difference Method——Based on Ningxia Sample Area

在"可持续生计框架"下,利用宁夏中卫、盐池、平罗3个县的农户调查数据,采用倍差法,厘清了退耕还林工程对农户生计资本的净效应。研究发现,总量上,退耕还林工程对农户生计资本的净效应为正,反映出退耕提高了农户发展能力。从不同类型生计资本来看,除了自然资本的净效应为负外,其余各项的净效应均为正,其中较大的有金融资本和物质资本。耕地被退耕成林地,是自然资本为负的主要原因,而政府对退耕地的补贴对于金融资本和物质资本的增加起决定性作用。

With the sustainable livelihood framework,this paper examined the net effect of the Sloping Land Con- version Program （SLCP） on farmers＇ livelihood asset. The DID （difference in difference） method is introduced and the data come from household survey from Zhongwei city, Yanchi county and Pingluo county in Ningxia. The results show that the total effect is positive, which implies the SLCP induced the increase of farmers＇ develop- ment ability. Moreover, the effect is also positive on every division of livelihood asset, except for natural asset. The main reason why the effect on natural asset is negative is farmers converted their croplands into forestlands, which is required by the SLCP. For the positive effect, especially on the financial asset and physical asset, the dominant fac- tors refer to farmland subsidies from governments.