Table A1

Control Variables Used in Analysis

MeanStandard Deviation
Birth weight 0–999 grams0.001
Birth weight 1,000–1,499 grams0.003
Birth weight 1,500–2,499 grams0.043
Birth weight 2,500–3,499 grams0.476
Congenital/perinatal 0–30.156
Number of congenital/perinatal 0–30.2220.587
Congenital/perinatal 4–80.016
Number of congenital/perinatal 4–80.0270.263
Congenital/perinatal 9–130.012
Number of congenital/perinatal 9–130.0190.209
Congenital/perinatal 14–180.013
Number of congenital/perinatal 14–180.0190.208
Mother married at birth0.843
Mother < 20 at birth0.073
Mother > = 20, < 25 at birth0.298
Mother > = 25, < 35 at birth0.581
Mother 35 + at birth0.048
Child male0.514
Child first born0.308
Child second born0.377
Child third born0.191
Child fourth born0.072
Child fifth born or higher0.052
Number of children in family = 20.294
Number of children in family = 30.342
Number of children in family = 40.18
Number of children in family = 50.184
Birth year 19790.076
Birth year 19800.1
Birth year 19810.119
Birth year 19820.154
Birth year 19840.171
Birth year 19850.139
Birth year 19860.118
Birth year 19870.123
Number of observations50,404