Green returns to education: Does education affect pro-environmental attitudes and behaviors in China?

population. As illustrated in Fig 1, the junior secondary school enrollment rate dramatically increased from 68.4% in 1985 to 98.4% in 2005. Meanwhile, the illiteracy rate fell from 23.5% in the 1982 to 6.72% in the 2000 according to national census. In the meantime, the implemen- tation of the CSL is a great exogenous factor with respect to personal educational attainment in China, because it is independent of individual preferences and economic conditions and cannot be adjusted in advance. Hence, we utilize this shock to construct an instrumental vari- able for education, which will be explained in detail in the identification strategy section. 3. Data, variables, and models 3.1. Data Our main source of data is the Chinese General Social Survey (CGSS), which is a comprehen- sive database that aims to systematically monitor the changing relationship between social structure and quality of life in both urban and rural China. Initiated in 2003, the CGSS is one of the earliest national representative cross-sectional survey projects in China. Since 2010, the survey has been conducted annually by the National Survey Research Center (NSRC) at Renmin University of China. The respondents are required to be age 18 and above. We use the 2010 round of CGSS data to explore whether there are green returns to educa- tion in China, because it is the only wave that contains information about respondents’ pro- environmental attitudes and behaviors as well as environmental knowledge, and is in the

meantime publicly available. In 2010, the survey covers 11,783 respondents, residing in 134 cit- ies across 31 of China’s provinces. To shorten questionnaire length and improve survey com- pliance, some modules in CGSS 2010 are randomly assigned to a subset of respondents. For example, for questions on environmental attitudes and behaviors, only those born in February, September, November, or December are asked. Thus, our study can only use approximately one third of the sample. We dropped the observations with missing values for variables that are used in the analysis and end up with 3,661 observations. We conduct a balancing test based on a range of observational variables between the regression sample and the dropped sample to check whether there exists a severe sample selection issue. The results, shown in S2 Table in S2 Appendix, suggest that the two samples are similar in observational characteristics, which gives us further confidence in the representativeness of our regression sample. 3.2 Variables 3.2.1 Pro-environmental attitudes and behaviors. The CGSS 2010 asks respondents three questions regarding the willingness of their pro-environmental attitudes (Question 12 in L part of the survey) and six questions about the frequency of their pro-environmental behav- iors (Question 20 in L part of the survey). For three attitude questions, respondents are asked to rate their willingness to pay higher prices, higher taxes and to lower their standard of living for environmental protection based on five ordinal scales: (i) “Extremely unwilling to”; (ii)

“Reluctant”; (iii) “Do not care”; (iv) “Willing to” and (v) “Extremely willing to”. As for the six pro-environmental behaviors, taking waste recycling for example, the respondents are asked whether they have taken any actions to separate wastes for recycling, and they need to indicate how often they carry out such actions given three ordinal options: (i) “Not at all”, (ii) “Occa- sionally” and (iii) “Frequently”. The exact wording of other environmental behaviors is pro- vided in Table 1. Table 1 summarizes the pro-environmental attitudes and behaviors. Specifically, Panel A reports the proportion of respondents providing “Extremely unwilling”, “Reluctant to”, “Do not care”, “Willing to” and “Extremely willing to” answers to each of the three pro-environ- mental attitudes questions, while Panel B shows the distribution of respondents providing PLOS ONE Green returns to education PLOS ONE | https://doi.org/10.1371/journal.pone.0263383 February 3, 2022 5 / 20