Fascinating recent paper from UVA’s Chloe Gibbs finds impressive results from full-day kindergarten, as compared to half-day. Specifically, children randomly assigned to full-day kindergarten in Indiana demonstrated stronger literacy skills at the end of kindergarten, with an estimated effect size of .3 standard deviations overall and an even greater impact of .7 standard deviations for Hispanic children.
These results are important for several reasons:
First, these are very large effect sizes for an educational intervention. The effect size for full-day kindergarten for Hispanic students was roughly 70% of the end of kindergarten achievement gap for children in the control group.
Second, while access to full-day kindergarten has expanded over the past two decades, it’s still far from universal. About 75% of kindergartners nationally are in full-day programs.
Third, the cost effectiveness of this intervention was impressive. Using cost estimates for the program, Gibbs calculated an effect size of 0.07-0.2 standard deviations per $1,000 spent on full-day kindergarten, which compares very favorably to similar estimates for other educational and early childhood interventions.
Finally, the circumstances that enabled this study shed light on the ridiculous nature of early childhood education policy. In 2007, Indiana decided to expand access to full-day kindergarten (at the time only 41% of kindergarten slots were full-day). But it did not do so by changing its state funding formula–which provides a 0.5 weight for children enrolled in kindergarten, whether half or full-day–to provide a full weight for kindergartners enrolled in full-day programs. Instead, it created a grant program that districts could apply for to make up the difference. This, combined with the fact that any district that applied received funding and that grants were allocated based on kindergarten enrollment, meant that districts did not have sufficient funding to provide full-day kindergarten to all students. So districts needed to create mechanisms to allocate the limited supply of full-day kindergarten slots–in some districts, a lottery. Great for Gibbs’ research–but lousy for kids. And just another example of the striking contrast in how public/government systems fund the pieces of the education system that we agree to be mandatory or an entitlement for students compared to those we don’t. There’s no inherent reason to believe that 5-year-olds should only go to school for half a day and 6-year-olds a full day, but because kindergarten is historically half-day in many places, providing 5-year-olds (already seen as children who should be in public schools) a full-day of school is seen as a luxury expense in a way that a full-day of school for, say, 2nd graders, never is. This is dumb.