In his seminal work, Free to Choose,” Nobel Prize-winning economist Milton Friedman outlined his case for universal school choice, advocating for robust voucher systems for elementary and secondary education that “would give parents at all income levels freedom to choose the schools their children attend.” (emphasis added)

Friedman’s work laid the foundation for the broader school choice movement. He knew there would be opposition to his proposal departing from the one-size-fits-all status quo. But he also knew, as he wrote in Free to Choose, that school choice options such as vouchers would “keep emerging with more and more support.” He was right.

The school choice movement is proliferating like never before. States traditionally have worked to ensure children most at risk of being underserved by their neighborhood schools are prioritized in accessing school choice options – children from low-income families and children with special needs, for example. But today, states have the opportunity to think bigger about educational freedom—for all children, from all levels of income.

As of 2014, there are 40 private school choice programs in 24 states and the District of Columbia. In 2011, Arizona passed the nation’s first education savings account option, advancing the notion of “School Choice 2.0.”

ESAs allow parents to use a portion of the dollars that would have gone to their child in a public school toward fully customizing their child’s education by enabling them to purchase a variety of education-related services and products. It’s likely Friedman would have seen ESAs as a refinement of his original voucher idea.

ESAs—like most school choice measures—are currently reserved for low-income children and children with special needs. This is a good starting point, but it should not be the end goal. As school choice measures grow more innovative, they also should become more expansive.

Parents of all income levels should be free to choose the best educational option to meet their child’s individual needs.

School choice raises all boats, for all children. As University of Arkansas professor Jay Greene writes, “Suburbanites need education reform for the sake of their own children and not just for the poor kids in the big cities. If suburban elites commit to education reform for their own children, we may finally get improvement for low-income kids in the cities as well.” Broader educational opportunity creates competitive pressure on public schools, which in turn benefits children who choose to attend.

What’s more, suburban educational options are not as good as they often are thought to be. The National Assessment for Educational Progress’ latest “report card” shows that only 26 percent of 17-year-olds are proficient in math, and only 38 percent are proficient in reading.

Research from the George W. Bush Institute’s Global Report Card shows even affluent American suburban schools districts lag in educational achievement compared to 25 other developed countries.

Friedman’s vision for school choice was not confined to a particular demographic or geographic area. Rather, he knew expanding opportunity across income levels would help both the poor and the affluent alike by creating a healthy competitive pressure on public schools and by empowering the ones who know their children best—parents—to choose the best educational options for their children. Research shows parents are more satisfied with their child’s education when they have the power to choose.

School choice options should be designed to give every child an opportunity to receive the best education possible. That is a 21st century vision for education reform.