Sociodemographic indicators for the samples in the three areas
| All | Hangzhou Urban | Xiaoshan Rich rural | Chunan Poor rural | |
|---|---|---|---|---|
| *Data for household income was available for only 81% of the sample. | ||||
| n (%) | 4197 | 1577 (38) | 1388 (33) | 1232 (29) |
| Male | 2153 (51.2) | 791 (50) | 720 (52) | 642 (52) |
| Female | 2044 (48.8) | 786 (49.8) | 668 (48) | 590 (48) |
| Mean age (SD) | 14.2 (1.69) | 14.2 (1.5) | 14.3 (1.7) | 14.1 (1.9) |
| Parents’ education (%) | ||||
| Neither completed middle school | 29 | 2.4 | 35 | 54 |
| One completed middle school | 27 | 11 | 44 | 31 |
| Both completed middle school | 44 | 86 | 22 | 14 |
| Household income* (%) | ||||
| <$150/month | 39 | 21 | 38 | 59 |
| >$150/month | 42 | 63 | 41 | 22 |
| Family size (%) | ||||
| One child family | 56 | 91 | 54 | 11 |
| Two children | 41 | 17.9 | 43 | 81 |
| Three children | 2.3 | 0.4 | 1.3 | 5.8 |
| Four or more children | 0.8 | 0.3 | 0.4 | 2.1 |
| % Boys only children | 64 | 90 | 75 | 16 |
| % Girls only children | 47 | 92 | 35 | 4.9 |
| Household composition (%) | ||||
| Natural parents only | 77 | 75 | 80 | 77 |
| Parents + other relatives | 15 | 12 | 14 | 17 |
| One parent/relatives: parent(s) working away | 2.2 | 1.5 | 1.9 | 3.4 |
| One parent/relatives: parents separated/divorced | 2.4 | 6.0 | 1.2 | 0.08 |
| One parent/relatives: death of parent | 1.9 | 1.8 | 1.4 | 2.5 |