TABLE 2—
Special Supplemental Nutrition Program for Women, Infants, and Children (WIC) Participation and Health Investments
| Initiated Breastfeeding Probit Model Marginal Effects (P) | Logarithm of Weeks of Breastfeeding Ordinary Least Squares Model Coefficients (P)a | At Least 4 Well-Child Visits Probit Model Marginal Effects (P)b | ||||
| Parsimonious Model | Larger Model | Parsimonious Model | Larger Model | Parsimonious Model | Larger Model | |
| Participated in WIC | 0.071 (.022) | 0.074 (.026) | −0.154 (.135) | −0.113 (.290) | 0.054 (.005) | 0.060 (.002) |
| Child’s age | −0.001 (.599) | −0.001 (.497) | −0.002 (.539) | −0.002 (.585) | −0.001 (.257) | −0.001 (.298) |
| Mother is foreign born | 0.396 (.000) | 0.384 (.000) | 0.808 (.000) | 0.715 (.000) | −0.015 (.374) | −0.023 (.222) |
| Mother is Hispanic | 0.074 (.294) | 0.058 (.392) | −0.015 (.885) | −0.073 (.461) | −0.024 (.239) | −0.030 (.094) |
| Mother is African American | −0.087 (.054) | −0.102 (.013) | 0.205 (.027) | 0.159 (.096) | −0.062 (.000) | −0.061 (.000) |
| Mother is Asian | −0.097 (.368) | −0.079 (.473) | −0.496 (.107) | −0.461 (.143) | 0.008 (.903) | 0.012 (.858) |
| Mother is Native American | −0.015 (.825) | −0.011 (.859) | 0.007 (.938) | −0.017 (.843) | 0.012 (.654) | 0.010 (.721) |
| Mother is other race | −0.064 (.239) | −0.059 (.284) | −0.110 (.303) | −0.082 (.290) | −0.037 (.069) | −0.033 (.114) |
| Mother is high school graduate | 0.110 (.000) | 0.106 (.000) | 0.022 (.775) | 0.001 (.990) | 0.048 (.000) | 0.043 (.000) |
| Mother completed some college | 0.270 (.000) | 0.254 (.000) | 0.134 (.224) | 0.135 (.233) | 0.056 (.000) | 0.045 (.014) |
| Mother is college graduate | 0.377 (.004) | 0.350 (.004) | 0.794 (.000) | 0.865 (.001) | 0.027 (.578) | 0.011 (.806) |
| Log household income | 0.011 (.147) | 0.012 (.123) | −0.019 (.433) | −0.011 (0.646) | 0.000 (.967) | 0.000 (.999) |
| Mother’s age | −0.009 (.000) | −0.007 (.000) | 0.016 (.048) | 0.005 (.544) | −0.002 (.108) | −0.002 (.112) |
| Mother moved since child’s birth | 0.041 (.128) | −0.059 (.373) | −0.002 (.894) | |||
| Mother had another baby since child’s birth | −0.015 (.631) | −0.277 (.002) | −0.010 (.482) | |||
| Mother lives in own apartment or house | −0.015 (.570) | −0.002 (.970) | 0.003 (.781) | |||
| Mother is enrolled in Medicaid | 0.007 (.820) | −0.000 (.999) | −0.025 (.063) | |||
| Mother smoked in past 30 days | −0.027 (.492) | −0.283 (.089) | −0.022 (.202) | |||
| Mother is enrolled in school | 0.098 (.000) | −0.037 (.627) | 0.009 (.533) | |||
| Mother has worked since child’s birth | −0.020 (.501) | −0.146 (.158) | −0.006 (.513) | |||
| Child is low birthweight | −0.020 (.590) | −0.390 (.003) | −0.019 (.272) | |||
| Mother lives with at least 1 parent | −0.040 (.023) | −0.248 (.020) | −0.014 (.319) | |||
| Number of children in household | 0.002 (.976) | 0.065 (.015) | −0.003 (.589) | |||
| Mother smoked during pregnancy | −0.043 (.190) | 0.023 (.879) | 0.000 (.988) | |||
| Mother had prenatal care during first trimester | 0.044 (.134) | −0.006 (.940) | 0.010 (.599) | |||
| Child is physically disabled | −0.103 (.276) | 0.335 (.074) | 0.036 (.377) | |||
| N | 2136 | 2136 | 1063 | 1063 | 2107 | 2107 |
Note. All models included 19 dummy variables representing the city of residence at baseline. The coefficients on the 19 dummy variables representing city of residence and the coefficients on the intercepts in each model are not shown. Omitted category: nonparticipant, White, high school dropout, born in United States. We present Huber-adjusted P values with an additional adjustment for clustering at the city level. These P values are obtained from robust variance estimates that also account for the possibility that observations from the same city are not independent of each other. Marginal effects should be interpreted as the change in the probability of the outcome associated with a small change in the independent variable (for a continuous variable) or a discrete change from 0 to 1 (for a dummy variable).
aLogarithm of weeks of breastfeeding model is limited to the 1036 mothers of 2136 who initiated breastfeeding.
bSample size is 2107 instead of 2136 in well-child visits model because all observations of living in 1 city (n = 29) were associated with at least 4 well-child visits. These observations were dropped.