退耕还林工程对农户收入不平等影响的测度与分析——基于总收入决定方程的Shapley值分解

Measuring and Analyzing the Impact of Sloping Land Conversion Program on Rural Households' Income Inequality——Shapley Value Decomposition Approach for Total Income Decision Equation

【目的】研究退耕还林工程对农户收入不平等的影响,以检验退耕还林工程目标的实现情况,为政府相关部门调整退耕还林工程后续政策及实施其他生态恢复项目提供决策依据。【方法】基于四川、河北、陕西等6省(区)15个案例县1 158个样本农户1995—2012年的平衡面板数据,考虑参与退耕还林工程的总体影响和边际影响,建立样本农户总收入决定方程;以基尼系数、泰尔-L指数和泰尔-T指数作为衡量收入不平等的指标,采用Shapley值分解法对样本农户的总收入决定方程进行分解,全面系统评估退耕还林工程对农户收入不平等的影响。【结果】经验性结果显示,样本农户是否参加退耕还林工程和参加退耕还林工程面积对总收入的影响均为正且在1%水平上显著。1999—2012年,样本农户是否参加退耕还林工程和参加退耕还林工程面积对总收入基尼系数的贡献率呈先升后降的趋势,贡献率最高为2008年,是否参加退耕还林工程和参加退耕还林工程面积的贡献率分别为3.04%和4.55%;在变化趋势上,退耕还林工程对样本农户总收入泰尔-L指数和泰尔-T指数的贡献与对基尼系数的贡献基本一致。【结论】实施退耕还林工程增加了样本农户的总收入,但拉大了样本农户的总收入不平等。因此,就生态恢复工程对农户收入不平等可能产生的影响而言,有必要引起高度关注,实现生态恢复、农民增收与分配公平的多赢。

[ Objective ] The objective of investigating the effect of the sloping land conversion program （SLCP） on rural households＇ income inequality is to verify the process of the SLCP, and some policy implications are considered for the next stage of the SLCP. [ Method] Total income decision equations were built using unique panel dataset of 1 158 sample rural households from 15 counties in 5 provinces and 1 region to consider the marginal and the overall effects. The effect of the SLCP on rural households＇ total income was estimated with Shapley value decomposition approach by GINI coefficient, Theil-L coefficient and Theil-T coefficient. [ Result ] The empirical results indicated that the overall effect and marginal effect of the SLCP on rural households＇ total income were positive and significant at 0. 01 statistical level. The contribution of the SLCP to GINI coefficients of both the overall effect and marginal effect of rural households＇ income inequality had been rising, and then declining from 1999 to 2012. The contributions in 2008 of both the overall effect and marginal effect were the highest with 3.04% and 4.55% , respectively. Both Theil-L coefficient and Theil-T coefficient informed us the similar consequences. [ Conclusion ] The implementation of the SLCP increased the sample rural households＇ income, and also caused their income disparity. Therefore, attentions should be paid to the impact of the ecological restoration programs on the income inequality of rural households. Multi-win policies should be designed to tackle the matter for ecological restoration to raise rural households＇ income and reduce income equality.