Impacts of Michigan Transitional Kindergarten through third grade.

Transitional Kindergarten (TK) is a relatively new and under-researched model of early childhood education. Using data from Michigan TK, this study examines impacts for children (50% female, 78% White, 9% Black, 7% Hispanic) who enrolled at age 4 in 2014-2015 and 2018-2019 using a regression discontinuity design. Michigan TK improved kindergarten readiness (0.9 SD, N = 1,943) and third-grade math scores (0.2-0.3 SD, N = 15,680). It had no impact on ever being placed in special education from kindergarten through second grade, but it did cause earlier entry into special education in kindergarten (N = 15,704). Our findings add to the larger evidence base on early education programs and contribute substantially to the evidence base on TK specifically.