In my new book, From Preschool to Prosperity, I review the research evidence on whether the benefits of early childhood programs go beyond children from low-income families to include middle-class children. This research evidence suggests that preschool at age 4 has similar-sized benefits for low-income and middle-class children, but that child care and parenting programs seem to have benefits only for children from low-income families.

The research evidence on middle-class benefits of preschool is sparse, but the best evidence suggests that pre-K causes similar-sized increases in test score percentiles at kindergarten entrance for middle-class and low-income children. In Tulsa, the pre-K impact for middle-class children in increased test score percentiles is about 90% of the impact for lower-income children. In Boston, the pre-K impact for middle-class children in increased test score percentiles is about 70% of the impact for lower-income children.

The available evidence on how early test scores are related to adult earnings suggests that these test score percentile effects predict similar ratios of dollar effects on adult earnings. Thus, the Tulsa results predict that the lifetime dollar increase in adult earnings for middle-class children will be about 90% of the increase for low-income children.

However, even though the dollar earnings effects are similar, universal pre-K would still have significant income redistribution effects. Children from low-income families would be expected to have lower future earnings than children from middle-class families. Therefore, even though the dollar earnings effect is similar, the percentage boost to the future standard of living will be much higher for children from low-income families.

For child care and parenting programs, the evidence on how effects differ for children from different income groups is also sparse. For parenting programs, several studies of the Nurse Family Partnership program suggest that benefits are restricted to low-income families. For child care programs, research on the Infant Health and Development Program also suggest that the benefits of high-quality child care are restricted to low-income children.

Why is the available research evidence sparse? In part, because there are simply more research funds available to study the effects of early childhood programs on low-income families. This research funding situation is likely to persist. So policymakers trying to determine the design of early childhood programs will have to make do with sparse information on the universality of these programs’ benefits.

Why might early childhood programs have this pattern of effects, with benefits for middle-class children more apparent for pre-K than for child care and parenting programs? Perhaps the benefits for pre-K in developing social skills are hard for middle-class parents to duplicate on their own, especially given the high price of high-quality private pre-K. In contrast, perhaps parenting and child care is somewhat easier for many middle-class parents to provide on their own.

If the goal of early childhood program design is to maximize the benefits for improving children’s future life course, this research suggests that there is support for universal pre-K, and support for income-targeted child care and parenting programs. One important caveat: this only counts benefits for children. Child care programs may have important benefits for parents that may be more broadly shared across income groups, and which also deserve consideration by policymakers.

Universality of pre-K programs can be backed by good evidence of broad benefits for diverse groups of child participants. In contrast, universality of child care programs would need to be justified by important benefits for diverse groups of parents.