Table 1.
Variable definition and summary statistics.
| Variable | Definition | N | Mean | S.D. |
|---|---|---|---|---|
| Panel A. Indicators of psychological problems (SDQ method) | ||||
| Psychological problems | Degree of student psychological problems as measured by SDQ method (0–60 points) | 12,096 | 8.579 | 10.270 |
| Emotional symptoms | Subscale of SDQ (0–12 points) | 12,096 | 2.058 | 2.647 |
| Conduct problems | Subscale of SDQ (0–12 points) | 12,096 | 1.590 | 2.069 |
| Inattention | Subscale of SDQ (0–12 points) | 12,096 | 1.835 | 2.366 |
| Peer relationship problems | Subscale of SDQ (0–12 points) | 12,096 | 1.529 | 2.135 |
| Prosocial problems | Subscale of SDQ (0–12 points) | 12,096 | 1.567 | 2.173 |
| Panel B. COVID-19 shock | ||||
| COVID19*Post | Shock variable of DID. 1 = adolescent in cities hit by COVID-19 in 2020; 0 = surveying in 2017 or adolescent in cities barely affected by the COVID-19 in 2020 | 12,096 | 0.608 | 0.488 |
| Panel C. Control variables | ||||
| Gender | Girls = 0; boys = 1 | 12,096 | 0.481 | 0.500 |
| Age | Adolescent age (years old) | 12,096 | 16.21 | 1.099 |
| Hukou | Rural = 0; Urban = 1 | 12,096 | 0.454 | 0.498 |
| Migrant | Whether the student is a migrant child (no = 0; yes = 1) | 12,096 | 0.083 | 0.276 |
| Elite class | Whether the student is in an elite class (no = 0; yes = 1) | 12,096 | 0.193 | 0.394 |
| Health | Adolescent physical health status through self-assessment (1 = poor; 2 = general; 3 = good; 4 = very good; 5 = excellent) | 12,096 | 3.546 | 1.043 |
| Only child | Whether the student is an only child (no = 0; yes = 1) 1 = unschooled; 2 = primary school; 3 = junior middle school; 4 = specialized secondary school; 5 = vocational high school; 6 = senior high school; 7 = junior college; 8 = bachelor degree; 9 = master’s or Ph.D. degree | 12,096 | 0.323 | 0.468 |
| Schooling of father | 12,096 | 4.338 | 1.988 | |
| Schooling of mother | 1 = unschooled; 2 = primary school; 3 = junior middle school; 4 = specialized secondary school; 5 = vocational high school; 6 = senior high school; 7 = junior college; 8 = bachelor degree; 9 = master’s or Ph.D. degree | 12,096 | 3.949 | 1.999 |
| Father’s occupation | 1 = the adolescent father is a national civil servant; enterprise manager; teachers, engineers, doctors, lawyers and other high-tech occupations; 0 = other occupations | 12,096 | 0.168 | 0.374 |
| Wealth | Relatively household wealth (1–5 from low to high) | 12,096 | 2.891 | 0.618 |
| Internet | whether there is a computer at home with Internet access (no = 0; yes = 1) | 12,096 | 0.859 | 0.348 |
| Board | Boarding at the school from Monday to Thursday (no = 0; yes = 1) | 12,096 | 0.715 | 0.451 |