中文摘要：

本文基于CHIP（中国家庭收入调查）（2002年）数据，实证研究了我国城市居民的社会资本对其收入水平和差异的影响。在其他条件相同的情况下，居民收入会随着自身社会资本的改善而提高。社会资本对收入差距的影响可以分解为两种不同的机制：（1）即使个体的社会资本相同，由于社会资本的收入回报率的异质性，社会资本在不同的收入群体中会产生扩大收入差距的影响；（2）给定社会资本的收入回报率相同，个体社会资本量的异质性也会扩大收入差距。笔者用分位数回归方法分析了社会资本的收入回报率在不同收入水平上的分布，从而验证了第一类机制。给定社会资本的收入回报率相同，使用夏普利值分解的方法发现，个体社会资本量的异质性会加剧收入差距的扩大，但是这一贡献并没有区域、行业特征等因素显著。随后的实证分析检验了社会资本对收入确实有提高作用，同时也分析出社会资本可能会缩小收入差距。这加深了我们对于社会资本在经济发展中微观机制的理解，并对制定消除收入差距的政策有指导意义。

英文摘要：

This paper uses the 2002 CHIP data to study the effects of social capital on income inequali- ty in urban areas. The main results show as follows： First, social capital can significantly raise income. Its marginal contribution increases with parents＇ education, which is dependent from parents＇ political capital. Second, using quartile regressions, Shapley value decomposition and Brown decomposition, this paper dis- tinguishes the return deficit and capital deficit which link social capital distribution to income distribution. We find that social capital plays a less important role than education, industry and region in their contribu tion to the overall income inequality. Finally, this paper conducts various robustness checks and concludes that social capital is not an important factor that causes income inequality in urban areas during the time period covered by the survey.