The Future of Children, Princeton - Brookings: Providing research and analysis to promote effective policies and programs for children.

In recent years, about one in five American children—some 12 to 14 million—have lived in families in which cash income failed to exceed official poverty thresholds. Another one-fifth lived in families whose incomes were no more than twice the poverty threshold.^1,2 For a small minority of children—4.8% of all children and 15% of children who ever became poor—childhood poverty lasted 10 years or more.³

Income poverty is the condition of not having enough income to meet basic needs for food, clothing, and shelter. Because children are dependent on others, they enter or avoid poverty by virtue of their family's economic circumstances. Children cannot alter family conditions by themselves, at least until they approach adulthood. Government programs, such as those described by Devaney, Ellwood, and Love in this journal issue, have been developed to increase the likelihood that poor children are provided with basic necessities. But even with these programs, poor children do not fare as well as those whose families are not poor.⁴

What does poverty mean for children? How does the relative lack of income influence children's day-to-day lives? Is it through inadequate nutrition; fewer learning experiences; instability of residence; lower quality of schools; exposure to environmental toxins, family violence, and homelessness; dangerous streets; or less access to friends, services, and, for adolescents, jobs? This article reviews recent research that used longitudinal data to examine the relationship between income poverty and child outcomes in several domains.

Hundreds of studies, books, and reports have examined the detrimental effects of poverty on the well-being of children. Many have been summarized in recent reports such as Wasting America's Future from the Children's Defense Fund and Alive and Well? from the National Center for Children in Poverty.⁵ However, while the literature on the effects of poverty on children is large, many studies lack the precision necessary to allow researchers to disentangle the effects on children of the array of factors associated with poverty. Understanding of these relationships is key to designing effective policies to ameliorate these problems for children.

This article examines these relationships and the consequences for children of growing up poor. It begins with a long, but by no means exhaustive, list of child outcomes (see Table 1) that have been found to be associated with poverty in several large, nationally representative, cross-sectional surveys. This list makes clear the broad range of effects poverty can have on children. It does little, however, to inform the discussion of the causal effects of income poverty on children because the studies from which this list is derived did not control for other variables associated with poverty. For example, poor families are more likely to be headed by a parent who is single, has low educational attainment, is unemployed, has low earning potential, and is young. These parental attributes, separately or in combination, might account for some of the observed negative consequences of poverty on children. Nor do the relationships identified in the table capture the critical factors of the timing, depth, and duration of childhood poverty on children.^6,7

This article focuses on studies that used national longitudinal data sets to estimate the effects of family income on children's lives, independent of other family conditions that might be related to growing up in a low-income household. These studies attempt to isolate the effect of family income by taking into account, statistically, the effects of maternal age at the child's birth, maternal education, marital status, ethnicity, and other factors on child outcomes.^2,8 Many used data on family income over several years and at different stages of development to estimate the differential effects of the timing and duration of poverty on child outcomes. The data sets analyzed include the Panel Study of Income Dynamics (PSID), the National Longitudinal Survey of Youth (NLSY) , Children of the NLSY (the follow-up of the children born to the women in the original NLSY cohort), the National Survey of Families and Households (NSFH), the National Health and Nutrition Examination Survey (NHANES), and the Infant Health and Development Program (IHDP). These rich data sets include multiple measures of child outcomes and family and child characteristics.

This article is divided into four sections. The first focuses on the consequences of poverty across five child outcomes. If income does, in fact, affect child outcomes, then it is important not only to identify these outcomes but also to describe the pathways through which income operates. Accordingly, in the second section, five pathways through which poverty might operate are described. The third section focuses on whether the links between poverty and outcomes can reasonably be attributed to income rather than other family characteristics. The concluding section considers policy implications of the research reviewed.