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. Author manuscript; available in PMC: 2014 May 1.
Published in final edited form as: J Health Econ. 2013 Feb 12;32(3):487–503. doi: 10.1016/j.jhealeco.2013.01.004

Table 1.

Variable Means

All Texas Births (N=4,193,778) Sibling Analysis Sample (N=485,048) Mothers w No Hurricane < 30km During Any Pregnancy (N=477,080) Mother Ever had a Hurricane < 30km During Pregnancy (N=7,968) Hurricane < 30km During Pregnancy (N=3,430)
Mother’s age <20 0.145 0.132 0.132 0.154 0.149
Mother’s age 20–24 0.280 0.297 0.297 0.324 0.311
Mother’s age 25–34 0.468 0.486 0.487 0.448 0.457
Mother’s age 35–44 0.107 0.085 0.085 0.074 0.083
Mother’s age 45+ 0.0007 0.0003 0.0003 0.0003 0.0003
Mother’s ed: <HS 0.311 0.281 0.282 0.264 0.247
Mother’s ed: HS degree 0.329 0.341 0.341 0.374 0.386
Mother’s ed: some college 0.159 0.157 0.157 0.160 0.161
Mother’s ed: college+ 0.191 0.211 0.212 0.199 0.202
Mother is married 0.648 0.679 0.679 0.654 0.668
Mother is non-Hispanic white 0.368 0.425 0.423 0.524 0.531
Mother is black 0.118 0.168 0.170 0.067 0.066
Mother is Hispanic 0.475 0.376 0.375 0.395 0.389
Child is male 0.511 0.511 0.511 0.518 0.520
Birth weight (g) 3298 (SD=557) 3329 (SD=523) 3329 (SD=523) 3325 (SD=520) 3333 (SD=525)
Low birth weight (<2500g) 0.063 0.053 0.053 0.053 0.054
Gestation (weeks) 38.600388 (SD=2.039) 38.672 (SD=1.721) 38.673 (SD=1.722) 38.581 (SD=1.692) 38.571 (SD=1.715)
C-Section Delivery 0.276 0.282 0.282 0.283 0.294
Induced Labor 0.216 0.200 0.198 0.273 0.271
Mother smoked during pregnancy 0.059 0.066 0.065 0.093 0.097
Average #cigarettes per day 0.506 (SD=2.612) 0.585 (SD=2.832) 0.582 (SD=2.826) 0.779 (SD=3.203) 0.786 (SD=3.221)
Mother gained <16 lbs 0.120 0.121 0.121 0.121 0.120
Mother gained >60 lbs 0.032 0.031 0.031 0.031 0.027
Number prenatal visits 10.799 (SD=4.254) 11.350 (SD=4.179) 11.345 (SD=4.184) 11.598 (SD=3.869) 11.675 (SD=3.785)
Adequate prenatal care 0.744 0.784 0.783 0.818 0.827
Variables Available 1996–2004 Only N=2,741,605 N=301,683 N=296,130 N=5,553 N=2,418
Any Abnormal Conditions of Newborn 0.056 0.051 0.051 0.082 0.096
Any Assisted Ventilation 0.040 0.038 0.038 0.045 0.040
Assisted Ventilation 30+ Minutes 0.008 0.007 0.007 0.012 0.019
Meconium Aspiration Syndrome 0.002 0.003 0.003 0.021 0.035
Hyaline Membrane Disease 0.005 0.005 0.005 0.004 0.003
Arterial Blood Gas pH <7.2 0.009 0.004 0.004 0.017 0.022
Any Complications Labor/Delivery 0.156 0.133 0.133 0.164 0.177
Moderate/Heavy Meconium 0.047 0.043 0.043 0.064 0.073
Premature Rupture of Membranes 0.013 0.010 0.010 0.010 0.010
Dysfunctional Labor 0.027 0.014 0.015 0.012 0.015
Breech/Malpresentation 0.027 0.026 0.026 0.028 0.031

Notes: The “All Texas Births” sample omits births with missing gestation or birth weight. The analysis sample is the universe of singleton sibling births with gestation >26 weeks in Texas between 1996–2008 whose mothers lived within 100km of areas that were ever struck by a storm or hurricane over this period. Mothers who live in Austin and San Antonio (both at the 100km boundary) are omitted. There were 8 hurricanes or storms (>40mph windspeed and >$10 million in property damages) over 1996–2008. Births to mothers who have at most one child with non-missing gestation or birth weight data are omitted from the sample. For 1996–2004 variables, births to mothers who have at most one child with non-missing data for any abnormal condition or complications from labor/delivery are also omitted (183,428 births).

The total analysis sample sizes for variables about maternal pregnancy behavior (smoking, number cigarettes, weight gain, and prenatal care) and characteristics of delivery (c-section, induced labor) range from 439,837 to 483,354.

Timing of exposure is calculated using information on the child’s birth date and child’s gestation length (in weeks) to calculate approximate date of conception. Texas changed the abnormal conditions of the newborn and the complications of labor/delivery that are reported on the birth certificate in 2005.