Since the Great Society era of the 1960s, hundreds of studies have documented positive effects of early childhood programs. Advances in knowledge have contributed not only to the development and improvement of programs but have also spurred expansion of services across the nation (Barnett, Epstein, Friedman, Sansanelli, & Hustedt, 2009; Zigler, Gilliam, & Jones, 2006).
These policy changes have been motivated by the synergy of three sets of findings. First, early childhood development (ECD) programs large and small, mostly focused on children ages 3 and 4, have demonstrated strong effects on school readiness, including language and literacy, numeracy, and socio-emotional skills (Camilli, Vargas, Ryan, & Barnett, 2010; Gormley, 2007; Karoly, Kilburn, & Cannon, 2005; Reynolds, Wang, & Walberg, 2003). Given the connection between school readiness and later performance, early education is a reliable strategy for enhancing child development outcomes. Second, ECD programs can affect broader well-being in ways ranging from preventing child maltreatment and crime to promoting health behavior (Campbell, Ramey, Pungello, Sparling, & Miller-Johnson, 2002; Reynolds et al., 2007; Schweinhart et al., 2005). Most other social programs do not show such broad and enduring impacts. Finally, ECD programs have demonstrated high levels of cost effectiveness by reducing the need for later remediation and treatment and increasing social benefits (Burr & Grunewald, 2006; Rolnick & Grunewald, 2003, 2007; Temple & Reynolds, 2007). Thus, they are widely considered to be more economically efficient investments than other social programs.