社会保障的基本目标是给贫困人口或者面临贫困威胁的人口提供财政支持。基于1978-2018年全国财政社会保障支出 (SSE) 与城乡收入差距(URIG)和农村贫困 (RPHR) 相关数据，本文采用协整检验分析方法，对社会保障支出的缓贫效果进行实证分析。结果表明在研究时期内财政社会保障支出与城乡居民可支配收入差距呈正相关关系，但影响非常有限，99%的城乡居民收入差距变化均是变量自身引起的。财政社会保障支出对农村贫困减少发挥了积极的作用，农村贫困发生率对社会保障支出的弹性值为-0.2255。因此，需要更多的财政社会保障支出以及更公平的社会保障制度体系，充分发挥社会保障制度的功能，这将成为2020年打赢脱贫攻坚战后缓解相对贫困的政策工具。
Social security has, as one of its primary aims, the provision of financial support to those deemed to be poor or facing the threat of poverty. Based on China’s national statistical data covering social insurance, social assistance, and social welfare between the period 1978–2018, this paper evaluates the effect of social security expenditure in reducing income inequality and rural poverty with cointegration analysis. It was found that there is a positive correlation between social security expenditure and the income gap of urban and rural residents in the long run, but the effect is very limited; nearly 99% of the changes of the urban–rural income gap come from its own contributions. Further research also shows that the elasticity of rural poverty incidence to social security expenditure is –0.2255, which indicates social security expenditure helps reduce rural absolute poverty. Based on these findings, the policy implications can be that much social security expenditure and a more equitable social security system should be encouraged. It will become one of the major anti-poverty strategies after 2020 in China when we win the battle against absolute poverty.