Association for Public Policy Analysis & Management

High quality early childhood education (ECE) programs have been shown to alter children’s life trajectories and yield substantial social returns. A growing body of research finds that children who attend publicly-funded preschool exhibit stronger academic skills than similar peers without access (Philips et al., 2017). At the same time, there is also growing evidence that the benefits are variable and that the initial gains from attending preschool may dissipate quickly as children progress through school. This is a troubling finding, especially in light of the substantial investments states are making in expanding access to publicly-funded early childhood programs. There is an urgent need for rigorous research examining which characteristics of preschool programs are needed to ensure larger and longer-lasting benefits.

One characteristic particularly worthy of examination is the length of the preschool day. Two recent studies indicate that children do better in preschool (Robin, Frede, & Barnett, 2006) and kindergarten (Gibbs, 2014) programs with extended days. These findings support the notion that extending from half- to full-day for four-year old children could bolster any positive impacts of preschool There may also be indirect benefits of access to full-day preschool for families given that half-day programming may be an impractical childcare option for working and single-parent families. Our current study adds to the small existing literature on this topic by providing new experimental evidence about the impacts of full-day preschool, on a host of immediate- and medium-term outcomes.

Prior to 2016, Westminster Public Schools—a predominantly low-income, non-White, and ELL district near Denver—provided only half-day preschool, four days per week. In 2016-17, WPS created nine new full-day classrooms as part of a Full-Day Pre-K Pilot Program. Because about twice as many families wanted to attend full-day than could be accommodated in those classrooms, WPS sought to select students based on a lottery system. We leverage this as an opportunity to randomly assign students to an offer of full- versus half-day preschool for three cohorts of students entering preschool in August of 2016, 2017, and 2018.

Results from our first cohort indicate meaningful benefits from full-day preschool on a set of cognitive outcomes, both at the end of the preschool year, and at kindergarten entry. By fall 2018, the first and second cohorts will have enrolled in grades one and two, respectively. We will present findings on initial impacts for both cohorts and on achievement and behavioral outcomes as these children move through the early elementary grades. In particular, our findings will indicate the causal effects of full versus half day pre-k offers on reading achievement, special education designation rates, daily attendance, and student measures of socio-emotional development. Because we also hypothesize that access to full-day childcare may have important effects on parents, we also estimate causal effects of full-day preschool on parental employment, childcare costs, time spent in alternative forms of childcare, maternal stress, and activities that parents engage their children in at home.