Table 3.
Internal balancing tests
| Coloured and African | Coloured | African | ||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Difference (Teen - Older) | Std. Error | T-stat | Sign. Diff. | Difference (Teen - Older) | Std. Error | T-stat | Sign. Diff. | Difference (Teen - Older) | Std. Error | T-stat | Sign. Diff. | |
|
| ||||||||||||
| Age | 0.05 | 0.40 | 0.12 | 0.31 | 0.56 | 0.56 | −0.48 | 0.35 | −1.37 | |||
| African | 0.02 | 0.06 | 0.36 | |||||||||
| Defines childhood household as poor | 0.02 | 0.05 | 0.37 | −0.01 | 0.06 | −0.18 | 0.06 | 0.07 | 0.93 | |||
| Log of mean household income in Wave 1 subplace | −0.03 | 0.07 | −0.45 | −0.01 | 0.06 | −0.18 | −0.02 | 0.11 | −0.19 | |||
| Own 5 books | 0.02 | 0.07 | 0.27 | −0.10 | 0.07 | −1.45 | 0.28 | 0.09 | 3.21 | ** | ||
| Mother’s highest level of education | −0.01 | 0.33 | −0.04 | −0.15 | 0.45 | −0.33 | 0.31 | 0.45 | 0.69 | |||
| Father’s highest level of education | −0.28 | 0.46 | −0.60 | −0.65 | 0.61 | −1.07 | 0.62 | 0.68 | 0.91 | |||
| Proportion childhood lived with mother | −0.04 | 0.04 | −0.98 | −0.03 | 0.05 | −0.57 | −0.05 | 0.05 | −1.03 | |||
| Proportion childhood lived with father | −0.06 | 0.07 | −0.75 | −0.02 | 0.10 | −0.22 | −0.12 | 0.07 | −1.58 | |||
| Proportion childhood lived with maternal grandparent | 0.05 | 0.04 | 1.17 | 0.04 | 0.05 | 0.87 | 0.05 | 0.06 | 0.80 | |||
| Drugs in childhood household | 0.05 | 0.04 | 1.30 | 0.09 | 0.06 | 1.62 | −0.03 | 0.03 | −1.05 | |||
| Alcoholic in childhood household | 0.06 | 0.05 | 1.05 | 0.08 | 0.07 | 1.07 | 0.01 | 0.06 | 0.18 | |||
| Highest grade by age 12 | 0.01 | 0.15 | 0.09 | 0.00 | 0.16 | −0.03 | 0.12 | 0.21 | 0.56 | |||
| Failed grade by age 12 | 0.00 | 0.07 | −0.03 | 0.02 | 0.09 | 0.23 | −0.05 | 0.11 | −0.47 | |||
| LNE score | −0.18 | 0.17 | −1.10 | −0.08 | 0.22 | −0.36 | −0.40 | 0.25 | −1.61 | |||
| Age of menarche | −0.29 | 0.19 | −1.52 | −0.27 | 0.27 | −1.01 | −0.39 | 0.18 | −2.22 | * | ||
| Age of sexual debut | −0.01 | 0.20 | −0.07 | 0.00 | 0.30 | 0.01 | 0.01 | 0.15 | 0.05 | |||
| Use condom at first sex | 0.12 | 0.06 | 2.00 | * | 0.10 | 0.08 | 1.32 | 0.15 | 0.08 | 1.92 | ||
The table presents variable means and the difference in means between teen and older mothers, the standard error of this difference and whether it is significant weighted using the CAPS sample weight, the inverse propensity score weight and the kernel weight. Variables included are those used in the propensity score. Differences marked with three asterisks (***) are significant at the 1% level, those marked with two (**) are significant at the 5% level, and those marked with one (*) are significant at the 10% level. The table shows that once the data are weight by the inverse propensity score weight or kernel weight differences between teen and older mother characteristics are minimal or ‘balanced’.