Table 2. Effect of air pollution on mental health, mediated by cognitive and non-cognitive ability, 2016†.
| Depression | Cognitive ability | Non-cognitive ability | Depression | |
|---|---|---|---|---|
| PM2.5 | 0.038*** (0.015) |
-0.059*** (0.011) |
-0.052*** (0.011) |
0.028* (0.014) |
| Cognitive ability | -0.112*** (0.011) |
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| Non-cognitive ability | -0.053*** (0.011) |
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| Covariates | Yes | Yes | Yes | Yes |
| County/District Fixed Effects | Yes | Yes | Yes | Yes |
| Observations | 13761 | 13761 | 13761 | 13761 |
| Adjusted R2 | 0.134 | 0.461 | 0.504 | 0.143 |
†Notes: Standard errors in parentheses.
* p < 0.1
** p < 0.05
*** p < 0.01. Depression is measured by the Center for Epidemiological Studies Depression Scale (CES-D). PM2.5 is a proxy for air pollution. Cognitive ability is composed of the score of immediate word recall test and the score of number series test, and non-cognitive ability is composed of the ability to express oneself (rated by the interviewers) and the extent of fluency of Mandarin (rated by the interviewers). To control for unobserved effects resulting from heterogeneity of different counties or districts which the interviewees live, county or district fixed effects are included in the models. OLS Model is employed in this table. The first column is run with depression regressed on PM2.5; the second column with the first mediator (cognitive ability) regressed on PM2.5; the third column with the second mediator (non-cognitive ability) regressed on PM2.5; and the fourth column with depression regressed on PM2.5 and both mediators (cognitive ability and non-cognitive ability).