外生活动冲击对周边农户粮食产出与收入的影响——以采矿活动为例

Impacts of Exogenous Activity Shocks on Grain Output and Income of Surrounding Farmers:An Example of Mining Activities

“三农”问题始终是我国现代化建设的根本问题,因而在工业活动中权衡收益与成本,关注其对农民生产生活的影响也至关重要。文章以农村固定观察点为样本,采用前沿的交叠双重差分(DID)方法,探讨采矿活动作为外生变量冲击对于周边农户粮食产出及家庭收入的影响。实证发现,采矿活动冲击会导致周边农户的粮食产出减少约20%,且一定时间内影响加剧,在不同识别框架中均稳健。粮食种植面积、家庭教育水平、是否位于粮食主产区等因素显著调节了家庭户所受负面影响,使不同特征的农户受影响程度不同。这些负面效应来源于减少投入和降低生产率两个渠道,生产率的降低一方面在要素投入既定的情形下减少了产出,即形成“阶梯产量”;另一方面又使得周边农户自觉减少要素投入,形成“弃种”现象。此外,采矿活动也显著影响了周边农户收入,使得种粮收入下降。总收入越低的家庭更“惜粮”“储粮”,经济福利损失更高,且可能导致总收入进一步降低;而总收入较高的家庭则相反。采矿活动对周边农户而言其收益不一定能抵消其成本,甚至可能导致贫富分化的“马太效应”。因此,政策应加强对矿区农民的精准福利补偿,切实保障农民利益。

The issues relating to agriculture, rural areas, and farmers have always been the fundamental issues in China’s modernization,so it is important to weigh the benefits and costs of industrial activities and pay attention to their impacts on farmers’ production and livelihoods. This paper investigates the impact of mining activities on the grain output and income of surrounding farmers by using a frontier staggered difference-in-difference method with samples of fixed rural observation sites. It’s found that mining activities reduce the grain output of the surrounding farm households by about20%, and the impact intensifies over time and is robust across different identification frameworks. Households with different characteristics have different degrees of negative impact,and factors such as planting acreage of grain,household education level,and location in major grain-producing region all significantly moderate their impact. These negative effect comes from both input reduction and productivity reduction. Productivity reduction reduces the grain output under the condition of stable factor input and also affect farmers who consciously reduce the factor input, resulting in the phenomenon of "abandonment of planting". In addition, mining activities significantly affect the income of neighboring farmers, resulting in the income decrease from grain cultivation and the income increase from wages, and has no significant change in final total income. The lower the total income,the higher the economic welfare loss. For surrounding farmers,the benefits of mining activities may not necessarily offset the cost,and may even lead to the "Matthew effect"(the polarization of wealth). Therefore, it should strengthen the precise compensation for farmers in mining areas to effectively protect their interests.