Christina M. Gibson-Davis

A Cautionary Tale: Using Propensity Scores to Estimate the Effect of Food Stamps on Food Insecurity

This article uses propensity scores to evaluate the effect of food stamps on food insecurity, a measure of inadequate food supply. It relies on data from the Early Childhood Longitudinal Study‐Kindergarten Cohort. By balancing treatment and comparison groups on covariates, the propensity score method adjusts for bias caused by observed variables. This method may be preferable to regression because it does not rely on a linear functional form to adjust for potential confounding variables. Results show that food stamps do not decrease the probability of being food insecure, although they lessen the severity of the problem according to some models. However, propensity scores rely on several stringent assumptions, including the need for a common support region (where two compared groups share the same characteristics) and a properly specified model. Propensity scores should therefore be employed with caution.

Connecting Child Care Quality to Child Outcomes Drawing Policy Lessons from Nonexperimental Data

Effective early childhood intervention and child care policies should be based on an understanding of the effects of child care quality and type on child well-being. This article describes methods for securing unbiased estimates of these effects from nonexperimental data. It focuses on longitudinal studies like the one developed by the National Institute of Child Health and Human Developments Early Child Care Research Network. This article first describes bias problems that arise in analyses of nonexperimental data and then explains strategies for controlling for biases arising from parental selection of child care. Next, it comments on attrition in longitudinal studies and outlines some strategies for addressing possible attrition bias. Finally, it discusses the need to translate “effect sizes” derived from these studies into the kinds of cost and benefit information needed by policy makers.

Early Childhood Family Structure and Mother-Child Interactions: Variation by Race and Ethnicity.

With data from the Early Childhood Longitudinal Study-Birth Cohort (n = 6,449), a nationally representative sample of births in 2001, we used hierarchical linear modeling to analyze differences in observed interactions between married, cohabiting, never-married, and divorced mothers and their children. In contrast to previous studies, we concentrated on early childhood, a developmentally critical period that has been understudied in the family structure literature, and relied on objective observational measures of mother-child interactions, which are unlikely to be biased by maternal perceptions of interactions with children. Nonmarital family structures were common in the lives of young children, as 32% lived outside of a married, biological parent home. Initial results indicated that married families were consistently associated with higher quality interactions. Moreover, though it was hypothesized that the presence of a biological father might be associated with higher quality interactions than single-parent households, this hypothesis was not confirmed. Additional models suggest that race and ethnicity moderated the effect of family structure, as non-Hispanic Black and non-Hispanic White participants showed little significant variation between married and unmarried families. Among Hispanics, mothers living in cohabiting, divorced, or single families, when compared to married mothers, exhibited more negative and more intrusive behaviors; cohabiting mothers also scored lower on the measure of cognitive stimulation. Results suggest that marriage may not be uniformly associated with higher levels of mother-child interactions and that cohabitation, particularly for Hispanics, may be associated with adverse outcomes.

Breastfeeding and Verbal Ability of 3-Year-Olds in a Multicity Sample

OBJECTIVES. Our goal was to analyze the effect of maternal verbal ability and education on the association between breastfeeding and children’s cognitive functioning. First, we hypothesized that maternal verbal abilities account for a large portion of the association between breastfeeding and child verbal abilities. Second, we hypothesized that after adjusting for maternal verbal abilities, a positive effect of breastfeeding will be most evident among highly educated mothers, because these mothers may have more opportunity to engage in cognitively stimulating parenting than do mothers with less education. PATIENTS AND METHODS. With data on 1645 American-born mothers participating in a longitudinal birth cohort study, we used linear regression to determine the influence of breastfeeding for at least 1 month on the Peabody Picture Vocabulary Test-Third Edition scores of 3-year-old children. Models were adjusted for an extensive set of demographic characteristics, including mother’s Peabody Picture Vocabulary Test and the Home Observation for Measurement of the Environment score. Mothers were categorized into 1 of 3 educational-status groups: no high school diploma, high school diploma, and some post–secondary education. RESULTS. In unadjusted mean comparisons, breastfed children had Peabody Picture Vocabulary Test scores that were 6.6 points higher than children who were not breastfed. After adjusting for demographic characteristics and maternal verbal ability, the coefficient dropped to 1.72. Among mothers with education beyond high school, the children’s Peabody Picture Vocabulary Test scores in adjusted models were 2.2 points higher for breastfed children. Among mothers with a high school diploma or less, there were no significant differences in the children’s Peabody Picture Vocabulary Test scores by breastfeeding status. These results were consistent in white, black, and Hispanic children. CONCLUSIONS. Maternal Peabody Picture Vocabulary Test scores mediate much of the association between breastfeeding and child verbal abilities. The beneficial effects of breastfeeding on children’s cognition may emerge only when breastfeeding is done in conjunction with other positive parenting behaviors. The advantageous effects of breastfeeding do not seem to be solely attributable to the superior nutrient content of breast milk.

Breastfeeding and the Child Cognitive Outcomes: A Propensity Score Matching Approach

To estimate the effect of breastfeeding initiation and duration on child development outcomes. 3,271 children and their mothers participating in the Child Development Supplement of the Panel Study of Income Dynamics provide data for these analyses. Main outcomes include Woodcock Johnson Psycho-Educational Battery-Revised (WJ-R) test score (letter word, passage comprehension, applied problem, and broad reading), and Wechsler Intelligence Scale for Children-Revised (WISC-R) test score at the 2002 survey. Controlled variables include family, maternal, and child characteristics, many of which can be traced back to the year the child was born. The analytic technique is propensity score matching with multiple imputations. After using propensity scores to adjust for confounding factors, breastfeeding initiation showed statistically significant effects but the practical scale remains small. Breastfeeding duration showed a non-linear effect on those outcomes and most of the effects are not significant. The effects of breastfeeding on child’s cognitive outcomes are modest in practical terms. The non-linear effects suggest that selection into breastfeeding may account for the increased score of children who are breastfed.

The effect of the WIC program on the health of newborns.

OBJECTIVE To determine the effect of the Special Supplemental Nutrition Program for Women, Infants, and Children (WIC) on birth outcomes. DATA SOURCE The Child Development Supplement (CDS) of the Panel Study of Income Dynamics (PSID). The PSID provides extensive data on the income and well-being of a representative sample of U.S. families from 1968 to present. The CDS collects information on the children in PSID families ranging from cognitive, behavioral, and health status to their family and neighborhood environment. The first two waves of the CDS were conducted in 1997 and 2002, respectively. We use information on 3,181 children and their mothers. STUDY DESIGN We use propensity score matching with multiple imputations to examine whether WIC program influences birth outcomes: birth weight, prematurity, maternal report of the infants health, small for gestational age, and placement in the neonatal intensive care unit. Furthermore, we use a fixed-effects model to examine the above outcomes controlling for mother-specific unobservables. PRINCIPAL FINDINGS After using propensity scores to adjust for confounding factors, WIC shows no statistically significant effects for any of six outcomes. Fixed-effects models, however, reveal some effects that are statistically significant and fairly substantial in size. These involve preterm birth and birth weight. CONCLUSIONS Overall, the WIC program had moderate effects, but findings were sensitive to the estimation method used.

Community-Wide Job Loss and Teenage Fertility: Evidence From North Carolina

Using North Carolina data for the period 1990–2010, we estimate the effects of economic downturns on the birthrates of 15- to 19-year-olds, using county-level business closings and layoffs as a plausibly exogenous source of variation in the strength of the local economy. We find little effect of job losses on the white teen birthrate. For black teens, however, job losses to 1 % of the working-age population decrease the birthrate by around 2 %. Birth declines start five months after the job loss and then last for more than one year. Linking the timing of job losses and conceptions suggests that black teen births decline because of increased terminations and perhaps also because of changes in prepregnancy behaviors. National data on risk behaviors also provide evidence that black teens reduce sexual activity and increase contraception use in response to job losses. Job losses seven to nine months after conception do not affect teen birthrates, indicating that teens do not anticipate job losses and lending confidence that job losses are “shocks” that can be viewed as quasi-experimental variation. We also find evidence that relatively advantaged black teens disproportionately abort after job losses, implying that the average child born to a black teen in the wake of job loss is relatively more disadvantaged.

Magic Moment? Maternal Marriage for Children Born Out of Wedlock

To test the existence of the “magic moment” for parental marriage immediately post-birth and to inform policies that preferentially encourage biological over stepparent marriage, this study estimates the incidence and stability of maternal marriage for children born out of wedlock. Data came from the National Survey of Family Growth on 5,255 children born nonmaritally. By age 15, 29 % of children born nonmaritally experienced a biological-father marriage, and 36 % experienced a stepfather marriage. Stepfather marriages occurred much later in a child’s life—one-half occurred after the child turned age 7—and had one-third higher odds of dissolution. Children born to black mothers had qualitatively different maternal marriage experiences than children born to white or Hispanic mothers, with less biological-parent marriage and higher incidences of divorce. Findings support the existence of the magic moment and demonstrate that biological marriages were more enduring than stepfather marriages. Yet relatively few children born out of wedlock experienced stable, biological-parent marriages as envisioned by marriage promotion programs.

Children and the Elderly: Wealth Inequality Among America’s Dependents

Life cycle theory predicts that elderly households have higher levels of wealth than households with children, but these wealth gaps are likely dynamic, responding to changes in labor market conditions, patterns of debt accumulation, and the overall economic context. Using Survey of Consumer Finances data from 1989 through 2013, we compare wealth levels between and within the two groups that make up America’s dependents: the elderly and child households (households with a resident child aged 18 or younger). Over the observed period, the absolute wealth gap between elderly and child households in the United States increased substantially, and diverging trends in wealth accumulation exacerbated preexisting between-group disparities. Widening gaps were particularly pronounced among the least-wealthy elderly and child households. Differential demographic change in marital status and racial composition by subgroup do not explain the widening gap. We also find increasing wealth inequality within child households and the rise of a “parental 1 %.” During a time of overall economic growth, the elderly have been able to maintain or increase their wealth, whereas many of the least-wealthy child households saw precipitous declines. Our findings suggest that many child households may lack sufficient assets to promote the successful flourishing of the next generation.

Midpregnancy Marriage and Divorce: Why the Death of Shotgun Marriage Has Been Greatly Exaggerated

Conventional wisdom holds that births following the colloquially termed “shotgun marriage”—that is, births to parents who married between conception and the birth—are nearing obsolescence. To investigate trends in shotgun marriage, we matched North Carolina administrative data on nearly 800,000 first births among white and black mothers to marriage and divorce records. We found that among married births, midpregnancy-married births (our preferred term for shotgun-married births) have been relatively stable at about 10 % over the past quarter-century while increasing substantially for vulnerable population subgroups. In 2012, among black and white less-educated and younger women, midpregnancy-married births accounted for approximately 20 % to 25 % of married first births. The increasing representation of midpregnancy-married births among married births raises concerns about well-being among at-risk families because midpregnancy marriages may be quite fragile. Our analysis revealed, however, that midpregnancy marriages were more likely to dissolve only among more advantaged groups. Of those groups considered to be most at risk of divorce—namely, black women with lower levels of education and who were younger—midpregnancy marriages had the same or lower likelihood of divorce as preconception marriages. Our results suggest an overlooked resiliency in a type of marriage that has only increased in salience.