Abstract: This paper uses the DID strategy to empirically analyze the effects of the New Rural Cooperative Serious Illness insuranceon rural residents' income and its transmission mechanism. The results confirm that the serious illness insurance has increased the per capita income of the low-income families by about 5 percentage points, but about 10-15 percentage points for the high-income families, which has led to an 11-percentage-point expansion of the Gene coefficient. The study of the transmission mechanism shows that the direct benefit of the rural social medical insurance is progressive and begins to tilt towards the poor. So the direct channel does not widen the income gap. Research on two types of potential indirect channels confirms that health rather than knowledge is an intermediary variable that affects residents' income. The serious illness insurance has increased the health level of the high-income group to a greater extent, thus indirectly expanding the income disparity. In order to change the disadvantaged position of the low-income group, efforts should be made to enhance the accessibility of medical services.

Key words: NCMS Serious Insurance, Income Distribution, DID, Mediation Effect

摘要： 本文实证检验了新农合大病保险对农村居民收入的冲击效应及其传导机制。研究结果证实,大病保险使得低收入组的家庭人均收入增长了约5个百分点,但是高收入组的家庭人均收入增长了10至15个百分点,从而导致农村居民收入基尼系数扩大了11个百分点。对传导机制的研究发现,农村社会医疗保险直接受益具有累进性,因此大病保险影响收入的直接渠道并未扩大居民收入差距。对两类潜在的间接渠道的研究证实,大病保险主要通过健康这一中介变量影响居民收入,而学历与技能的中介作用不明显。尽管大病保险对所有农村居民的健康水平均有正向作用,但高收入组的健康改善效应大于低收入组,因此大病保险通过放大健康不平等间接扩大了农村居民收入差距。本文的研究表明,中国农村社会医疗保险虽然实现了一定程度的过程公正,但是若要实现结果公正,还需进一步改变农村低收入群体在获取公共医疗服务中的弱势地位。

关键词: 新农合大病保险, 收入分配, 双重差分, 中介效应