Among scientists and educators, there's widespread agreement that early childhood development is essential for youngsters' long-term well-being.
In the U.S., politicians have taken notice. More than half of the candidates vying for the Democratic presidential nomination are advocating universal, federally funded preschool for children under five.
The political appeal of "Pre-K for all" is obvious, but the benefits aren't. A rush to universal pre-kindergarten risks creating a vast new entitlement that mostly subsidizes upper-income families. The goal should instead be getting more poor kids into high-quality programs.
Previous attempts in the U.S. to offer free universal pre-K have yielded uneven results. Most notably, the beneficiaries of such programs overwhelmingly tend to be poor and minority children; higher-income and white students derive little to no benefits from them.
One reason for this disparity is that most higher-income families already have access to good private preschools - and are willing to pay a premium for them.
A more targeted approach would help. Congress should work with states to makesure free, full-day preschool is available to all children in poverty.
In pursuing this goal, policy makers should be as flexible as possible. For instance, they should allow low-income parents to use vouchers to enroll their kids in privately run day-care centers.
Some states are already showing how it can work. A court-ordered expansion of pre-K in 31 high-poverty areas in New Jersey in the early 2000s required that local childhood education centers employ certified teachers, limit class sizes and undergo regular performance reviews. A 2017 study found that this expansion reduced the achievement gap for disadvantaged students by 15 percent if they received one year of preschool, and by as much as 40 percent if they went for two years.
As any parent knows, it's never too early to invest in the lives of children. When it comes to preschool, the U.S. should be sure to prioritize those who need it most.