成人高等教育作为高等教育的重要组成部分，也是推动继续教育体系建设和构建“学习型社会”的重要一环，尽管在理论上有着不可撼动的地位，但由于在现实中没有得到足够的重视，以及存在制度体系建设滞后、教育质量和声誉欠佳等问题，导致大众对其认可度不高，进而引发了成人高等教育是否应该继续、又应该如何发展等讨论。本文试图从教育回报率的角度为这些问题提供参考，通过估计成人高等教育的回报率，探究其是否存在经济回报、与普通高等教育相比又如何，并从人力资本理论和信号理论的角度进行解释，再对近10年成人高等教育回报率的变化情况进行讨论，并从学历获得年代入手探讨成人高等教育回报率的变化发展，以及其是否受到高校扩招的影响。

本文使用中国综合社会调查（CGSS）2006-2018年间共计9年的数据，使用OLS和分位数回归的方法对明瑟收入方程进行估计，具体研究以下两个问题：（1）成人高等教育整体以及成人专科、成人本科的回报率及变动趋势，分性别进行讨论，并对不同收入分位点进行对比研究，同时检验成人高等教育的人力资本效用和信号效用；（2）以学历获得年代为划分依据，研究以同种方式获得的同等学历的教育回报率随获得年代的变化趋势，以及这种变化是否受到高校扩招的影响。

研究发现：（1）相对于普通高中，接受成人高等教育具有显著正向的经济回报，且本科学历的经济回报高于专科学历，成人教育的回报率低于普通正规教育，这个结论在分性别的讨论以及各收入群体中均成立。同时，女性和低分位点上的成人高等教育回报率更高。成人高等教育回报率在2006年-2018年间表现出波动上升的趋势，成人本科回报率增长情况更好，成人专科回报率虽然波动更大，但整体上升的幅度不明显。成人本科相对于普通高中的正向经济回报是人力资本效应和信号效应共同导致的，而成人专科的正向经济回报是由人力资本效应导致的。（2）在不同年代以同种方式获得同等学历的教育回报率存在差异，越早获得的成人高等教育的回报率越高，但进入20世纪90年代以后，获得学历的不同时期对回报率影响不大。高校扩招导致了成人高等教育回报率的下降，且成人本科回报率的下降幅度大于成人专科，成人专科和成人本科回报率受到高校扩招的影响大于普通专科和普通本科。

As an important part of higher education, adult higher education is an important link to promote the construction of continuing education system and build a "learning society". Theoretically, it has an unshakable status, however, it has not been paid enough attention to in reality. In the meantime, existing problems such as delayed system construction, poor quality of education and poor reputation have led to low public recognition. Therefore, the discussion on whether adult higher education should be continued and how to develop it has been evoked. This paper attempts to provide a reference for the above problems from the perspective of the returns to education. By estimating the returns to adult higher education, this article explores whether it affects financial return and the difference between it and ordinary higher education, and explains it from the perspectives of human capital theory and signal theory. Furthermore, it discusses the change in the returns to adult higher education in the past ten years and the influence of the year of obtaining the diploma on the change and development of the returns on adult higher education. We also explore whether this change is affected by the expansion of university enrollment.

Based on the data from the Chinese General Social Survey (CGSS) from 2006 to 2018, this paper estimates Mincer's income equation using OLS and quantile regression and specifically studies the following questions: (1) The overall return and trend of adult higher education, as well as adult college and adult undergraduate degree, which are classified by gender and different income groups. At the same time, the human capital utility and signal utility of adult higher education will be tested; (2) this paper also studies the changing trend of the return of the same level of educational qualifications obtained in different years. Is it affected by the expansion of enrollment in universities?

The findings are as follows: (1) compared with ordinary high schools, the economic return on undergraduate degrees is higher than that of college degrees, while the returns on adult education is lower than that of regular education. This conclusion holds for different gender and all income groups. The returns on adult higher education showed a trend of fluctuation rising from 2006 to 2018. The growth of adult undergraduate return rate is better, while the fluctuation of adult college return is bigger, the overall increase is not significant. The positive economic return of adult undergraduate education relative to ordinary high school is caused by the combination of human capital effect and signal effect, while the positive economic return of adult college education is caused by human capital effect. (2) There are differences in the rate of return of education obtained in the same way in different years. The earlier the adult higher education degree is obtained, the higher the rate of return. However, after the 1990s, the different periods of obtaining the degree have little influence on the rate of return. The expansion of university enrollment has led to a decrease in the return rate of adult higher education, and the decrease in the return of adult undergraduate education is bigger than that of adult college education. The impact of university enrollment expansion on the return of adult college education and adult undergraduate education is greater than that of general college education and general undergraduate education.