Table 1.
Differences in Outcomes Between Brothers, by Birth Weight Sample: Boys with At least One Brother Who Does Not Have the Same Birth Weight Classification
| Low birth weight~ | Not low birth weight | Difference | |||
|---|---|---|---|---|---|
|
| |||||
| [1] | [2] | [1] minus [2] | |||
| Outcomes in childhood: child sample | |||||
| Proportion good/fair/poor health^ | 0.291 | [285] | 0.204 | [362] | 0.087 *** |
| Woodcock-Johnson achievement measures: | |||||
| Broad Reading standardized score | 89.57 | [37] | 96.22 | [46] | −6.65 ** |
| Letter/Word standardized score | 88.28 | [47] | 93.00 | [60] | −4.72 |
| Passage Comprehension standardized score | 93.00 | [37] | 98.93 | [59] | −5.93 * |
| Applied problem standardized score | 94.53 | [47] | 98.80 | [59] | −4.26 |
| Outcomes in adulthood: adult sample | |||||
| Proportion high school dropout^ | 0.189 | [265] | 0.158 | [514] | 0.031 |
| Proportion attended college^ | 0.374 | [265] | 0.374 | [514] | 0.000 |
| Proportion fair/poor adult health | |||||
| All ages | 0.146 | [957] | 0.082 | [2200] | 0.064 *** |
| 18–26 | 0.080 | [199] | 0.064 | [470] | 0.017 |
| 27–36 | 0.136 | [536] | 0.073 | [1223] | 0.063 *** |
| 37–52 | 0.230 | [222] | 0.120 | [507] | 0.109 *** |
| Proportion with no earnings | |||||
| All ages | 0.108 | [1100] | 0.061 | [2542] | 0.048 *** |
| 18–26 | 0.053 | [318] | 0.033 | [798] | 0.021 * |
| 27–36 | 0.126 | [565] | 0.054 | [1243] | 0.072 *** |
| 37–52 | 0.143 | [217] | 0.122 | [501] | 0.021 |
| Annual earnings, including 0s | |||||
| All ages | $20,390 | [1100] | $26,047 | [2542] | −$5,657 *** |
| 18–26 | $15,773 | [318] | $17,541 | [798] | −$1,768 ** |
| 27–36 | $20,164 | [565] | $26,886 | [1243] | −$6,722 *** |
| 37–52 | $27,743 | [217] | $37,511 | [501] | −$9,768 ** |
| Annual earnings, excluding 0s | |||||
| All ages | $22,863 | [981] | $27,727 | [2388] | −$4,863 *** |
| 18–26 | $16,664 | [301] | $18,132 | [772] | −$1,468 * |
| 27–36 | $23,062 | [494] | $28,418 | [1176] | −$5,356 *** |
| 37–52 | $32,367 | [186] | $42,712 | [440] | −$10,345 * |
| Annual hours, including 0s | |||||
| All ages | 1,331 | [1803] | 1,438 | [4132] | −107 *** |
| 18–26 | 991 | [904] | 1,042 | [2112] | −52 |
| 27–36 | 1,623 | [677] | 1,812 | [1509] | −188 *** |
| 37–50 | 1,824 | [222] | 1,972 | [511] | −148 ** |
| Wages | |||||
| All ages | $11.92 | [990] | $13.66 | [2409] | −$1.74 *** |
| 18–26 | $9.05 | [297] | $10.02 | [755] | −$0.97 * |
| 27–36 | $12.46 | [502] | $13.85 | [1189] | −$1.39 ** |
| 37–52 | $14.97 | [191] | $19.10 | [465] | −$4.13 * |
Number of observations reported in brackets.
*
significant at 10%;
**
significant at 5%;
***
significant at 1%.
^
Girls are included for the analysis of child health and educational attainment to increase sample size.
~
For the child outcomes, the number of cases were too small to consider only low birth weight. So for these outcomes the comparison is between siblings who did and did not have poor birth outcomes, where poor outcome is defined as being born less than 5.5 pounds or before 37 weeks (i.e., premature).