Imagine that you’ve decided to buy a car. You go to the dealership but instead of choosing a model that will last you hundreds of thousands of miles, you select a car that is poorly rated and already has a lot of wear and tear. Over the years, you decide that putting additional money toward maintaining your car isn’t important. You take shortcuts on repairs, and before you know it, your car can barely make it to your local grocery store, much less complete a cross-country road trip.

This shouldn’t be surprising. After all, you get what you pay for, right?

Yet time and again, policymakers expect hundreds of thousands of miles out of early childhood programs that are not adequately funded and maintained. Critics like to say that we don’t know if early childhood programs work, suggesting that the research is inconclusive. But we can’t expect much mileage from programs whose funding is constantly under threat, whose teachers are paid less than parking lot attendants, and whose budgets can’t accommodate a full school day or school year.

Here’s what we do know: Early childhood programs work, but they have to be high quality. A large body of research suggests that children who participate in high-quality early learning programs gain anywhere from four to 12 additional months of reading and math skills. High-quality programs can also boost children’s social-emotional development and physical health.

We also know what quality looks like in child care and preschool classrooms. It includes learning through play; teachers who are well-paid and knowledgeable of child development; and child-friendly activities, routines and classroom environments.

Perhaps most important, we know that quality is costly to provide, and that parents can’t shoulder any more of the financial burden than they already do.

Yet, despite all that we know, the United States continues to underfund child care and preschool year after year, resulting in programs that are inherently limited in scope and impact.

On average, states spent just $4,489 per child in public preschool in 2015 — roughly one-third the amount spent per child in programs rated as high-quality. Meanwhile, federal spending on early care and education decreased by 3 percent from 2013 to 2014. Existing child care assistance rates don’t cover the cost of center-based care in many states, which can set parents back up to $18,000 per year for an infant and a 4-year-old child.

Programs working with constrained budgets have to choose between sacrificing critical quality components, or making high-quality services accessible to only a small number of children and families. In fact, of the nearly 2.8 million 4-year-olds enrolled in any center-based preschool program across the country, it is estimated that only one-third of them are in a high-quality classroom.

Moreover, much of the current funding for early care and education is concentrated in the preschool years, when children are 3 to 4 years old. Federal spending on infants and toddlers barely exceeds $600 per child per year. This runs contrary to the fact that a rapid period of development takes place between the ages of zero and 3, as children are learning to walk, talk and interact with the world. A narrow focus on the year or two before children enter kindergarten means that we are missing a critical opportunity to support children’s learning when they are most formative.

We can no longer take shortcuts. If we want the children of today to become the productive, healthy citizens of tomorrow, we must put our money where our mouth is. We must invest in and maintain high-quality child care and universal preschool programs so that all children have the opportunity to thrive.

It’s time to stop perpetuating the false notion that we know nothing about whether and how early childhood programs work. Like that car, child care and preschool programs can’t run on fumes. It’s time to give these programs the necessary resources to provide quality services in every state, city and classroom.