It sounds too good to be true: Free, universal preschool for 3 and 4-year-old kids. For working parents, and those who wish they could go back to work (or even just go to the grocery store alone) the idea seems like a beautiful, if unrealistic, dream.

Except that some places—including America's capital city—have figured out how to make universal preschool a reality. In Washington, D.C., 90% of 4-year-olds and 70% of 3-year-olds attended a full-day preschool program for free, according to the Center for American Progress.

Preschool for everyone. For free.

Those two years of no-cost, high-quality preschool have a huge impact on families.

First, the preschoolers are reaping the benefits of preschool. High-quality, center-based care has a ton of benefits, but surprisingly, they're not academic. A recent study published in the Journal of Epidemiology & Community Health found children who attended high-quality center-based care for at least one year had lower rates of emotional, conduct, relationship and attention problems later in life than kids who were watched by a family member or babysitter. These benefits last longer than any temporary boost the kids get in academics.

The second benefit is economic. The incredibly expensive cost of childcare is a huge barrier to paid work for many parents who simply wouldn't be able to afford day care. When D.C. tore down this barrier, the city's maternal work force participation rate increased by more than 10%.

Universal preschool for 3 and 4 year olds has been proven to be doable and beneficial for families and the wider community.

So why isn't America moving toward universal preschool?

Well, for one thing, money.

The ways in which states and school districts fund preschool programs vary across America.

Funding for preschool programs can come from the federal, state and local governments, and even the private sector, but the ratios depend on the state you're in.

Basically, universal preschool programs have to be championed at the state level, and different states have wildly different ideas about how important preschool is, who should have access and how to fund it.

Some states fund preschool programs with gambling revenue. Others have funneled money from tobacco settlements into educating 4-year-olds. Utah famously made a bet with Goldman Sachs to fund preschool for kids from low-income homes.

The U.S. Constitution puts the responsibility of education on the states, but state constitutions vary. Some explicitly protect the rights of preschoolers to public education, while others (looking at you, Idaho) are arguably more open to interpretation on this issue.

D.C and several other states include preschool or "voluntary prekindergarten" funding in their education funding formula, a model that research suggests is the best, most stable was to fund these programs. In the 2016-17 school year, D.C. spent $16,996 in state funding per child, as overseen by the Office of the State Superintendent of Education. The national average? Just $5,008.

But where do those thousands of dollars come from? Federal funding typically makes up a very small piece of the pie for K-12 funding, usually under 10%. The next biggest chunk of funding is from the state but and local governments make up the bulk of funding for K-12 education in America. So if universal preschool is part of a K-12 funding model, taxpayers are paying for it.

According to the National Institute for Early Education Research, 18 states got federal Preschool Development Grants in 2017, while seven states didn't invest any state money in preschool at all.

As Steve Barnett of the National Institute for Early Education Research told NPR, "The growing inequality between states that have moved ahead and invested in quality preschool programs and states that have done nothing is really stark."

In the Dakotas, Utah, Wyoming, Idaho, and New Hampshire, state dollars don't go to preschool programs (Montana just recently got its pilot program up and running).

But in Florida, voluntary prekindergarten has been free for all 4 year old children for years, and Georgia also boasts a long-standing free-to-all prekindergarten program. It's the same story in Oklahoma, where 74% of four-year-olds attend school.

Vermont, California and Wisconsin also offer Pre-K programs, and West Virginia, Alabama, New York, Michigan and Rhode Island have all increased pre-K enrollment rates in recent years. So too have Mississippi and New Jersey.

But pre-K isn't always universal preschool

What sets such state programs apart from D.C.'s universal preschool programs is that in some states, not every child will qualify for enrollment, making the preschool not "universal." And, pre-K is often just for 4-year-olds. Eighty-six percent of kids in state-funded preschool programs are 4 years old, but there are plenty of 3 year olds who are ready for preschool.

There's another layer here too that makes D.C.'s system so enviable: In D.C., preschools must offer at least 6.5 hours of care per day, but in many states pre-K is just a half-day program. In some states pre-kindergarteners might be in school for only a few hours a week. There are few jobs parents can work within that small window of time.

Still, economists estimate the potential benefits of such pre-K programs are several times greater than the costs, not because parents are getting back to work, but because of lower societal costs (like lower spending on the criminal justice system and social support programs) and greater future earning potential for pre-K graduates.

If the economic returns of one year of half day pre-K is good, then imagine what a full day of care for two years could do if expanded nationwide.

Universal preschool in other nations

It's not surprising that many other countries have already figured out what D.C. did and implemented it on a wider scale.

Since 2000 all British 4-year-olds have access to part-time preschool, and the plan was extended to 3-year-old children in 2005. No surprise, maternal workforce participation rates went up there, too.

In Norway, almost all preschoolers go to free preschool and the practice is regarded as a citizen's right after 30 years of steadily increasing enrollment.

France has it. Finland has it. Spain has it. Mexico has it. China is aiming for it, with a goal of getting 85% of 3 to 6 year old kids into preschool by 2020.

Closer to home, the Canadian province of Québec has something that's not quite universal preschool (the demand is too high to get all the kids into the high-quality center-based care), but rather a steeply subsidized childcare program that saw women's workforce participation go from 74% to about 87% over a couple decades, CBC reports.

The rest of Canada is still waiting for relief from sky-high day care costs and so, of course, is America. But the blueprint for it is right there in the capital city of the United States.

Universal preschool has made D.C. a better place for families, and it's time to make it truly universal for all Americans.

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