A preschooler at Fords Prairie Elementary burns off energy after lunch in the school's multipurpose room in December 2016.
Cheerleaders for high-quality preschool programs, especially those subsidized with public dollars, face a frequent criticism: Although preschool may prepare more children for kindergarten, research hasn't yet produced enough evidence that the programs yield long-lasting benefits to justify the cost.
A five-year study released in 2015, for example, found that early gains for low-income students who enrolled in Tennessee's preschool program disappeared after only one year. And by third grade, the effects in some cases were negative.
That raised some concerns that perhaps Tennessee grew its program too quickly, and in turn lowered classroom quality. But in Oklahoma, where state law mandates high-quality standards for all preschool providers, new findings from a study of 4,000 participating children suggest their academic progress lasts well through middle school.
The study, published earlier this month in the Journal of Policy Analysis and Management, found that eight years after students who went through Tulsa's universal preschool program continued to perform better in math, were more likely to enroll in advanced courses and were less likely to repeat a grade than their peers who never enrolled in the program.
"The most important finding was that the kids who are in pre-K (prekindergarten) are less likely to be retained a grade," said Bill Gormley, a professor at Georgetown University's McCourt School of Public Policy and co-author of the new report.
"That's super important because the consequences of grade retention ... tend to be quite negative," such as higher rates of criminal behavior and lower earnings as an adult, he said. "Any policy intervention that can substantially reduce the likelihood of grade retention is a tremendous boon for the kids and their families and ultimately a boon for taxpayers."
The study estimated the long-term impact of lowering grade-retention rates for students produces a two-to-one return on what the public spends on Tulsa's preschool program.
In 1998, Oklahoma became the second state in the nation to offer universal preschool to all 4-year-olds, regardless of income. The city of Seattle launched a similar pilot program in 2015, and early results suggest it is helping more children get ready for kindergarten.
In Tulsa, Gormley and his co-authors had expected to see benefits from preschool participation on reading test scores, grade-point average, special education, student absenteeism and suspension rates. But the data didn't show any statistical significance for those outcomes.
The study also found mixed results depending on a student's gender or race: The positive effects on enrollment in honors courses were more pronounced for male students, and Latino students benefited much more in the long run than their black peers.
"We're still scratching our chins to figure out why African-American students are not experiencing quite as many gains as other students," Gormley said.
He noted that, although all students were less likely to repeat a grade, black students are more likely to be suspended, regardless of whether they finished preschool. And recent studies have tied racial disparities in classroom discipline to the performance gap.
