Table 2.
Descriptive statistics for the WLS sibling sample.
| Variable | Mean | S.D. | N |
|---|---|---|---|
| Years of schooling | 13.64 | 2.41 | 10,384 |
| Cognitive ability | 102.29 | 15.19 | 9,471 |
| Sibship size | 3.41 | 2.47 | 10,384 |
| Firstborn | .31 | .46 | 10,384 |
| Lastborn | .24 | .43 | 10,384 |
| Birth spacing to next older sibling | 3.76 | 2.79 | 10,324 |
| Birth spacing to next younger sibling | 4.06 | 3.00 | 10,300 |
| Log family income | 3.94 | .67 | 9,956 |
| Father’s years of schooling | 9.82 | 3.41 | 10,384 |
| Mother’s years of schooling | 10.50 | 2.80 | 10,384 |
| Father’s SES | 33.01 | 21.46 | 10,295 |
| “Broken” family | .08 | .28 | 10,384 |
| Farm origin | .20 | .40 | 10,384 |
| Respondent’s sex (=female) | .52 | .50 | 10,384 |