I have been discussing how the economic development benefits of pre-k vary across different income groups (e.g., lower class vs. middle class vs. upper class).  This is a key issue in deciding on the merits of “targeted pre-k”, which would focus on expanding access to high-quality pre-k for more disadvantaged children, versus “universal pre-k”, which would seek to set up a program that is accessible to all children.  This also helps determine the distributional effects across income groups of any proposed expansion of preschool.

In an ideal world, we would have rigorous evidence measuring how the benefits and costs of preschool vary across children from different income groups. However, all the rigorous long-term research studies of pre-k programs focus on disadvantaged children. This is true of the three best long-term studies, the studies of the Perry Preschool program, the Abecedarian program, and the Chicago Child-Parent Center program. This is also true of many of the short-term studies of pre-k’s impact, for example many of the studies done by NIEER.

Some of the NIEER studies do look at states in which there is there are many non-poor children participating. For example, the Great Start Readiness Program in Michigan (formerly the Michigan School Readiness Program) focuses on children who exceed the Head Start income limit, which is set at the poverty line, but who are below 250% (later 300%) of the poverty line, or have at least one of 24 other risk factors (e.g., single parent, teenage parent, diagnosed family problems, low birth weight, and many others).  Evaluations suggest that this program is highly successful in raising kindergarten readiness for its target group.  Therefore, this study suggests that preschool works for the near-poor/working class/lower-middle class, at least for those with some other risk factor.

Other studies of state pre-k programs consider states that are closer to or at universal coverage. For example, the studies of Oklahoma, which has over 70% of its 4-year olds in the state-funded pre-k program, suggest that this program is also highly effective in raising kindergarten readiness.  West Virginia’s program, which enrolls over half of the state’s 4-year olds, and is not targeted by income in most counties, also seems to be effective in raising kindergarten readiness.

These studies of state pre-k programs with broad access suggest that “universal” pre-k programs can on average be effective. However, these studies do not directly look at the effects of preschool on more “advantaged children”. For example, someone could argue that these significant average effects found in Oklahoma and West Virginia could be due to large effects for disadvantaged children that mask zero effects or even negative effects for more advantaged children.

In subsequent blog posts, I will consider more direct rigorous evidence for effects of preschool for children from more advantaged families.