Table 1.
Determinants of the probability of having a low, very low, or extremely low birth weight baby, expressed as marginal effects.
| Independent Variables | Model 1 | Model 2 | Model 3 |
|---|---|---|---|
| Probability of Having a Baby with: | |||
| Low Birth Weight | Very Low Birth Weight | Extremely Low Birth Weight | |
| Cigarette Use | 0.043 (69.04) |
0.003 (14.47) |
0.0021 (10.71) |
| Mother’s Age | 0.0005 (17.93) |
0.00003 (2.88) |
0.00006 (6.19) |
| Mother Black | 0.035 (73.68) |
0.006 (30.07) |
0.007 (38.65) |
| Mother American Indian/Alaskan Native | −0.003 (−2.42) |
0.0006 (1.11) |
−0.0007 (−1.51) |
| Mother Asian/Pacific Islander | 0.005 (7.97) |
−0.00004 (−0.21) |
−0.0004 (−2.13) |
| Mother Hispanic | −0.007 (−21.50) |
−0.001 (−7.19) |
0.00001 (0.10) |
| Mother Married | −0.01 (−34.34) |
−0.002 (−17.65) |
−0.002 (−20.44) |
| Mother High School Graduate | −0.001 (−3.18) |
−0.00007 (−0.48) |
0.0005 (3.82) |
| Mother Some College | −0.003 (−7.49) |
−0.0002 (−1.01) |
0.0004 (2.78) |
| Mother College Degree | −0.012 (−22.87) |
−0.001 (−8.06) |
−0.001 (−7.39) |
| Mother Graduate Degree | −0.012 (−20.24) |
−0.002 (−8.43) |
−0.002 (−8.75) |
| Birth Order of Baby | −0.002 (−24.55) |
−0.0002 (−7.01) |
−0.0005 (−13.39) |
| Pounds Gained During Pregnancy | −0.002 (−155.04) |
−0.0004 (−81.51) |
−0.0005 (−99.55) |
| Pre-Pregnancy Weight | −0.0004 (−108.05) |
−0.00005 (−38.68) |
−0.00005 (−36.69) |
| Women Infants and Children | −0.004 (−12.10) |
−0.002 (−16.21) |
−0.003 (−27.10) |
| Male | −0.012 (−44.49) |
−0.0004 (−3.62) |
−0.0003 (−3.49) |
| Mother’s Height | −0.002 (−34.49) |
0.00006 (2.87) |
0.00007 (3.73) |
| Cesarean Delivery | 0.028 (87.40) |
0.011 (81.08) |
0.006 (54.45) |
| Part of Multiple Birth | 0.491 (289.26) |
0.102 (72.90) |
0.102 (66.25) |
| Medicaid | 0.006 (16.16) |
0.0009 (6.08) |
0.0006 (4.26) |
| Out of Pocket | −0.001 (−1.98) |
0.000005 (0.02) |
0.0008 (2.87) |
| Other Method of Payment | 0.003 (5.02) |
0.0009 (3.38) |
0.0007 (2.91) |
| In Hospital | 0.027 (23.93) |
0.001 (2.06) |
−0.0003 (−0.55) |
| February | −0.0008 (−1.22) |
−0.0004 (−1.53) |
−0.0003 (−1.46) |
| March | −0.001 (−2.11) |
−0.0002 (−0.81) |
0.0004 (1.52) |
| April | −0.0003 (−0.49) |
0.0002 (0.61) |
0.0005 (2.28) |
| May | −0.001 (−2.06) |
0.0001 (0.42) |
0.0006 (2.46) |
| June | 0.00007 (0.11) |
0.0003 (1.37) |
0.0003 (1.23) |
| July | −0.0008 (−1.33) |
−0.0002 (−1.13) |
−0.0001 (−0.68) |
| August | −0.002 (−3.07) |
−0.0005 (−2.22) |
−0.0004 (−2.05) |
| September | −0.002 (−3.36) |
−0.0001 (−0.63) |
−0.0002 (−1.05) |
| October | −0.0005 (−0.80) |
−0.000006 (−0.02) |
−0.0004 (−1.69) |
| November | 0.0005 (0.75) |
0.0002 (0.70) |
−0.0003 (−1.22) |
| December | −0.00007 (−0.01) |
−0.0001 (−0.51) |
−0.0004 (−1.89) |
Note. Z-statistics are in parentheses. The critical values for the z-statistics are 2.58 (2.33), 1.96 (1.64), and 1.64 (1.28) at the 1%, 5%, and 10% significance levels, respectively, based on a 2-tailed (1-tailed) test.