By Deborah Stipek
Many policymakers tout universal preschool as a strategy for reducing the achievement gap that exists before children begin school, and for preparing all children for the increased academic rigor of kindergarten. Some studies have shown long-term benefits of preschool, but many find that by about 3rd grade, the advantage children who attended preschool had over children who did not has disappeared—the so-called "fade out" effect. Studies that point to fade-out disappoint policymakers who want to see long-term returns on resources devoted to early-childhood education.
Is fade-out inevitable? No. Studies have shown definitively that investment in preschool can yield sustained effects and significant social and economic returns. But fade-out is common and remains a persistent reminder that simply providing preschool to low-income children is not sufficient to achieve long-term benefits.
If we want to sustain the effects of preschool, we need to look at what happens after children enter school. Clearly, the quality of schooling they receive in the early elementary grades matters. Poor instruction can undo the effects of high-quality preschool experiences. But instruction has to be more than good to sustain preschool effects; it has to build strategically on the gains made in preschool. Currently, instruction in the early elementary grades is typically not well aligned with—and therefore does not make effective use of—the advantages high-quality preschool confers. Recent analyses of national data by Vanderbilt University’s Mimi Engel and her colleagues, for example, indicate that much of the math instruction children receive in kindergarten repeats material they have already mastered before entering kindergarten. Repetition gives the children who did not have the benefit of preschool an opportunity to catch up, but it does not build on the gains children made in preschool, and thus does not make good on the preschool investment.