Table 1.
Descriptive statistics.
| Variable | Description | Obs | Mean | Std. Dev. | Min | Max |
|---|---|---|---|---|---|---|
| Dependent variable | ||||||
| Depression | 1–5 levels | 11,894 | 2.151 | 0.954 | 1 | 5 |
| Explanatory variables | ||||||
| ln_Income | Logarithm of household income (RMB) | 11,913 | 9.450 | 2.774 | 0 | 16.113 |
| ln_Income_squared | Square of logarithm of household income (RMB) | 11,913 | 96.993 | 35.722 | 0 | 259.632 |
| Instrument variables | ||||||
| Automation | Automation index | 11,913 | −0.461 | 1.333 | −6.190 | 4.235 |
| Automation_squared | Square of the automation index | 11,913 | 1.987 | 4.151 | 0 | 38.314 |
| Demographic characteristics | ||||||
| Age | Age | 11,913 | 45.452 | 13.135 | 18 | 75 |
| Age_squared | Squared term of age | 11,913 | 2238.403 | 1219.181 | 324 | 5,625 |
| Whether female | Yes = 1, No = 0 | 11,913 | 0.468 | 0.499 | 0 | 1 |
| Human capital characteristics | ||||||
| Education level | 1–13 levels | 11,909 | 5.483 | 3.389 | 1 | 13 |
| Health status | 1–5 levels | 11,909 | 3.688 | 1.026 | 1 | 5 |
| Whether migrants | Yes = 1, No = 0 | 11,885 | 0.155 | 0.362 | 0 | 1 |
| Social characteristics | ||||||
| Whether Hukou in urban | Yes = 1, No = 0 | 11,890 | 0.300 | 0.458 | 0 | 1 |
| Whether ethnic minorities | Yes = 1, No = 0 | 11,913 | 0.081 | 0.272 | 0 | 1 |
| Whether religious believer | Yes = 1, No = 0 | 11,913 | 0.095 | 0.293 | 0 | 1 |
| Whether CPC member | Yes = 1, No = 0 | 11,902 | 0.102 | 0.3024 | 0 | 1 |
| Working characteristics | ||||||
| Weekly working hours | Working hours per week | 11,913 | 43.915 | 23.376 | 0 | 88 |
| Whether having pension | Yes = 1, No = 0 | 11,898 | 0.742 | 0.437 | 0 | 1 |
| Whether having medical insurance | Yes = 1, No = 0 | 11,908 | 0.935 | 0.247 | 0 | 1 |
| Family characteristics | ||||||
| Whether married | Yes = 1, No = 0 | 11,913 | 0.806 | 0.395 | 0 | 1 |
| Family size | Number of members in the family | 11,904 | 2.947 | 1.518 | 1 | 44 |
| Number of children | Number of children in the family | 11,902 | 1.523 | 1.094 | 0 | 20 |
| Number of houses | Number of houses in the family | 11,845 | 1.119 | 0.661 | 0 | 11 |
| Socio-economic status | Whether in the middle-upper class of the society | 11,834 | 0.497 | 0.500 | 0 | 1 |
| Year dummy | ||||||
| Province dummies | ||||||
The education level is classified from 1 to 13: 1-without any education, 2-kindergarten, 3-primary school, 4-junior high school, 5-vocational high school, 6-ordinary high school, 7-techinical secondary school, 8-technical high school, 9-junior college (adult higher education), 10-junior college (regular higher education), 11-undergraduate (adult higher education), 12-undergraduate (regular higher education), 13-postgraduate and above. Health status is based on the classic Likert scale from 1 to 5 to represent 1-unhealthy, 2-relatively unhealthy, 3-general, 4-relatively healthy, 5-healthy. The meanings of dummy variables are all “Yes = 1, No = 0.”