ECONOMIC REPORT OF THE PRESIDENT

A meta-analysis by Duncan and Magnuson (2013) examines the distribution
of impacts for more than 80 programs, including Head Start, Abecedarian,
and Perry as well as dozens of other preschool programs. Overall, across all
studies and time periods, early childhood education increases cognitive and
achievement scores by 0.35 standard deviations on average, or more than
one-quarter of the kindergarten math test score gap between the highest
and lowest income quintiles (Duncan and Magnuson 2011). The estimated
impacts in the studies considered in Duncan and Magnuson (2013) are illustrated
in Figure 4-18, with bigger circles generally corresponding to studies
that enrolled more children. Figure 4-18 shows that the vast majority of
programs benefit children’s cognitive development and achievement at the
end of the program.
The downward slope of the line in Figure 4-18 suggests that the effect
sizes of early childhood education programs have fallen somewhat over
time. However, as discussed above, a new study by Kline and Walters (2015)
suggests that this pattern does not reflect declining program quality, but may
be driven in part by an improving counterfactual for students not enrolled
in the program being studied.
One likely source of the improving academic outcomes for children
who are not enrolled in Head Start or other more narrowly targeted programs
is the recent expansion of large, State-run public preschool programs.
Wong et al. (2008) examine five State-run preschool programs and find
positive impacts on achievement test scores. Gormley et al. (2005) evaluate
Oklahoma’s preschool program in Tulsa and find that children’s kindergarten
achievement significantly improved. While it is too soon to directly estimate
these programs’ long-term effects since the oldest participants have not
yet entered the labor force, Hill, Gormley and Adelstein (2015) find evidence
of a persistent improvement in the Tulsa program’s impacts through third
grade for some students. Recent evaluations find positive cognitive outcomes
at fourth grade of Georgia’s State-run preschool program (Fitzpatrick
2008) and some persistent, though smaller, effects of Georgia and Tulsa’s
programs through eighth grade (Cascio and Schanzenbach 2013). These
studies also show that, even when some participating children switch from
private programs (a phenomenon often referred to as “crowd-out”), there
can still be gains in achievement for these children who would have otherwise
been in private programs, perhaps because families can use the savings
from switching to a public program to make other positive investments in
their children. A new working paper has also found evidence of the nonacademic
impacts of universal preschool on criminal activity. Oklahoma’s
universal preschool program lowered the likelihood that African-American
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