Arizona and the Diffusion of Private Education

A very brief history of the country’s earliest-running universal school choice program

We’re more than three years into the first foray into universal private school choice. Arizona expanded its Empowerment Scholarship Accounts in 2022, shifting from a program primarily targeted toward students with disabilities to one open to all K-12 students in the state.

Right now, it’s our best case study in seeing how a universal ESA program evolves over time.

While three years is not much time in the grand scale of K-12 education reform, I want to see if there are any hints about how Arizona’s ESA participant pool might be changing.

We know the program is growing substantially. Prior to expansion, a little more than 12,000 students participated in the ESA program. That number ballooned by nearly 50,000 in the 2022-23 school year. The program grew by roughly 13,000 and 10,000 in 2023-24 and 2024-25, and as of the beginning of October 2025, more than 91,000 Arizona children are enrolled in the ESA.

My colleague Mike McShane hypothesized that school choice is subject to the same diffusion of innovation trends we see in the growth of various ideas and technologies. The kinds of people who are the earliest adopters are not the same kinds of people who join later. Think, for instance, of the people in your life who might still have a landline and compare them to the people you knew who grabbed the first line of iPhones.

There are a lot of reasons the average family joining the program for the first time in 2025 might look different from a family joining in 2022. They might place a higher premium on stability, for example. At the beginning of the 2022-23 school year, it seemed possible that anti-choice advocates would collect enough signatures to put reversing the expansion on the ballot. If there was a chance a family’s eligibility for the program could get taken away, a child could face a lot of instability. A family might have wanted to let the dust settle before enrolling.

Another example might be a family failing to find a suitable fit in the first couple years of the program, but as the supply side of the private education sector develops, they might find an alternative that makes the ESA work for them. Or, it might have taken a family longer to learn the program existed, a very possible situation for families not already enrolled in a private school in 2022.

With this framework in mind, here are two hypotheses(!) I have after looking at Arizona’s public-facing reports:

1. Flexibility trends younger

Whatever the reasons, we know that there are tens of thousands of ESA students who were not immediate adopters. It is valuable to see any trends in the enrollment counts. Below is a table depicting ESA enrollment by grade:

I’m drawn to the changes in kindergarten enrollment. In 2022-23, the first year Arizona’s ESA was universal, kindergarten students made up 12.57% of all ESA enrollment, a five point increase over 2021-22. It’s the only time a single grade constituted more than ten percent of the total ESA enrollment for a given year. From 2021-22 to 2022-23, first and second grades also saw substantial growth in total enrollment shares.

These trends suggest to me that parents with younger children are more likely to be early adopters of a new ESA program. It’s difficult to detect trends in 2024-25, as the impact of this 2022-23 kindergarten surge still swings the data—nearly ten percent of ESA students are in second grade.

2. Exposure Effects

As it would be expected, students with disabilities make up a much smaller percentage of Arizona ESA students after eligibility broadened to the whole K-12 population. Indeed, students with disabilities (SWDs) constituted about three out of five ESA students in 2021-22 (disability status was the primary, but not sole, target of the ESA at this time).

While students without disabilities now make up a much higher share of ESA enrollment, SWDs are still overrepresented in the Arizona ESA program compared to traditional public schools. That might not be so surprising, given there is no reason to expect these students to mass-exit just because the program became accessible to the whole K-12 population.

What might be surprising, however, is that the share of SWDs in the program is trending upward. At just over a percentage point per year, an ESA student is ever so slightly more likely to be a SWD. Put in raw numbers, 10,409 students with disabilities were in the ESA program in 2022-23 and 16,332 were enrolled in 2024-25. We don’t know the distribution of SWDs by grade, so it’s hard to know how much of this growth comes from switchers versus first-time kindergartners, but it is interesting that thousands of SWDs are entering the program years after eligibility became universal considering they had been eligible for the program for a decade beforehand.

My thought is the public exposure given to the program due to its expansion meant a lot of special needs parents learned about the program for the first time. Like many other public programs, school choice faces an awareness problem, after all.

That awareness problem exists beyond parents of SWDs. In fact, the parents most likely to know about an expanded school choice program are those currently using private education options, as their providers have an incentive to inform their clients about the public options available to them. The long-term question is how well information about the program spreads beyond this initial wave.

The Arizona Department of Education’s quarterly reports began identifying the number of ESA students with a prior enrollment in an Arizona public school in the 2023-24 school year. That year, about a third (33%) of ESA students had such a record. The next year, that percentage jumped to 39%. That means newcomers are becoming more likely to come from a public school background, which communicates to me the feasibility of private alternatives is becoming more known among the public school population.

(Interpreting these figures can be complicated. For more details about exactly how to parse the public-to-private “switcher” rate in Arizona, you can check out this great post by my colleague Marty Lueken.)

Keep paying attention

Perhaps the biggest takeaway should be that universal ESAs truly are worth paying attention to over time, not only from a sector-wide perspective where they are compared against public school enrollment, but also from a granular perspective where we can see who joins as the program matures.

The ideas I’ve shared here are just that—ideas—and they are by no means the only conclusions that can be drawn from my handful of datapoints. But I’d argue they can spark worthy conversations about the earliest-running universal ESA in the country.

This was originally published to our Substack.