Recent advances in developmental neuroscience suggest that experiences early in life have profound and enduring influences on the developing brain. Family economic resources shape the nature of many of these experiences, yet the extent to which they affect children’s development is unknown. Our team of neuroscientists, economists and developmental psychologists proposes to fill important gaps in scientific knowledge about the role of economic resources in early development by evaluating the first randomized controlled trial to determine whether unconditional cash gift payments have a causal effect on the cognitive, socioemotional and brain development of infants and toddlers in low-income U.S. families. Specifically, 1,000 mothers of infants with incomes below the federal poverty line from four diverse U.S. communities will receive monthly cash gift payments by debit card for the first 40 months of the child’s life. The high cash gift treatment group mothers (40% of all mothers) will receive unconditioned cash payments of $333 per month ($4,000 per year) via debit care for 40 months. Mothers in the low cash gift comparator (control) group (60% of all mothers) receive a nominal payment – $20 per month, delivered in the same way and also for 40 months. The $333 per month is an amount in the range of a variety of income assistance policies in the U.S. and has been shown to be associated with meaningful improvements for poor children in prior studies. In order to understand the impacts of the added income on children’s cognitive and behavioral development, we will assess high vs. low cash gift group differences at age 3 (and, for a subset of measures, at ages 1 and 2) on measures of cognitive, language, memory, self-regulation and socioemotional development. Brain circuitry may be sensitive to the effects of early experience even before early behavioral differences can be detected. In order to understand the impacts of added income on children’s brain functioning at age 3, we will assess, during a lab visit, high cash gift and low cash gift group differences in measures of brain activity (electroencephalogram [EEG]). EEG activity will also be assessed in an in-home visit at age 1. To understand how family economic behavior, parenting, and parent stress and wellbeing change in response to income enhancement, we will assess treatment/control differences in family expenditures, food insecurity, housing and neighborhood quality; family routines and time use; parent stress, mental health and cognition; parenting practices; and child care arrangements at child age 2 and, for a subset of these measures, child age 1. This study will thus provide the first definitive understanding of the extent to which income plays a causal role in determining early child cognitive, socioemotional and brain development among low-income families. It will inform not only our basic and applied scientific understanding of early development, but also shedding light on the role of anti-poverty policies in promoting the wellbeing of poor children.
One thousand infants born to mothers with incomes falling below the federal poverty threshold in four metropolitan areas in the United States are being assigned at random within metropolitan area to one of two cash gift conditions. The sites are: New York City, the greater New Orleans metropolitan area, the greater Omaha metropolitan area, and the Twin Cities. IRB and recruiting issues will likely lead to a distribution of the 1,000 mothers across sites of roughly 115 in one site (the Twin Cities) and 295 in each of the three other sites. The high cash gift treatment group mothers (40% of all mothers) will receive unconditioned cash payments of $333 per month ($4,000 per year) via debit care for 40 months. Mothers in the low cash gift comparator group (60% of all mothers) receive a nominal payment – $20 per month, delivered in the same way and also for 40 months. The 40/60 randomization assignment is stratified by site but not by hospitals within each of the four sites.
Mothers are being recruited in maternity wards of the 12 participating hospitals shortly after giving birth and, after consenting, are administered a 30-minute baseline interview. They then are asked to consent to the cash gifts. The three follow-up waves of data collection conducted at child ages 1, 2 and 3 will provide information about family functioning as well as developmentally appropriate measures of children’s cognitive and behavioral development. An additional feature of our ages 1-3 data collection plans is that we will randomly assign a designated interview date within a one-month interval centered on the child’s birthday. This provides variation in the timing of outcome data with respect to participants’ receipt of the cash gift that will enable us to learn more about the incremental value of a stable predictable monthly infusion of cash.
We will collect information about the mother and child in the home when the child is 12 and 24 months of age. At age 3, mothers and children will be assessed and interviewed in research laboratories at each site. Conditional on participants’ consent and our success in securing agreements with state and county agencies, we will also collect state and local administrative data regarding parental employment, utilization of public benefits such as Medicaid and Supplemental Nutrition Assistance Programs (SNAP), and any involvement in child protective services. We also have plans to randomly sample 80 of the participating families in two of the sites (the Twin Cities and New Orleans) to participate in an in-depth qualitative study, but do not elaborate on those plans in this document.
The compensation difference between families in the high and low cash gift groups will boost family incomes by $3,760 per year, an amount shown in the economics and developmental psychology literatures to be associated with socially significant and policy relevant improvements in children’s school achievement. (We have worked with state and local officials to ensure to the extent feasible that our cash gifts are not considered countable income for the purposes of determining benefit levels from social assistance programs.) After accounting for likely attrition, our total sample size of 800 at age 3 years, divided 40/60 between high and low payment groups, provides sufficient statistical power to detect meaningful differences in cognitive, emotional and brain functioning, and key dimensions of family context (see below).
Cognitive and emotional development measures will be gathered at 12, 24, and 36 months of age. At the age-three lab visit we will administer validated, reliable and developmentally sensitive measures of language, memory, executive functioning and socioemotional skills. We will also collect direct measures of young children’s brain development at ages 1 and 3. Measures and preregistered hypotheses about them as well as family-based measures are shown in the documents attached to this registry.
The family process measures that we will gather are based on two theories of change surrounding the income supplements: that increased investment and reduced stress will facilitate children’s healthy development. We will obtain data measuring both of these pathways annually. Investment pathway: Additional resources enable parents to buy goods and services for their families and children that support cognitive development. These include higher quality housing, nutrition and non-parental child care; more cognitively stimulating home environments and learning opportunities outside of the home; and, by reducing or restructuring work hours, more parental time spent with children. Stress pathway: A second pathway is that additional economic resources may reduce parents’ own stress and improve their mental health. This may allow parents to devote more positive attention to their children, thus providing a more predictable family life, less conflicted relationships, and warmer and more responsive interactions.