Since 2018, Oklahoma public school revenue has surged by more than $3 billion annually, with per-pupil revenue jumping more than 50 percent.

Since spring 2024, Oklahoma has also offered all families the option to attend private school using refundable tax credits of up to $7,500 per child, thanks to the Oklahoma Parental Choice Tax Credit program, which is currently capped at $250 million per year.

A new study suggests that the $250 million going to the Oklahoma Parental Choice Tax Credit program not only benefits the children who use it to attend private school but also has a positive impact on academic outcomes in public schools, equivalent to a direct funding increase of roughly $2.75 billion for Oklahoma’s K-12 public schools.

“School Choice Competition vs. New Education Spending: Estimating the Academic Benefits for Public School Students” finds that the competition created as more children use school-choice programs to attend private schools produces better outcomes in surrounding public schools as well.

The study, authored by Patrick Graff, senior fellow with the American Federation for Children, is a research synthesis that examined other sources, including a 15-year study of a Florida school-choice program released in 2023 and a meta-analysis of the effects of additional school spending on student achievement that was released in 2024.

“The results are striking: scaling the tax credit scholarship program from 15,000 to over 100,000 students produced achievement gains for public school students that were—conservatively—over 11x larger than if that same funding had been used to increase state K-12 education budgets instead,” Graff wrote. “Critics warned that expanding the state tax credits available to fund private school scholarships would come at the expense of public schools across the state. The best evidence we have suggests otherwise.”

The 2024 meta-analysis, which examined 31 studies across the country, found that over 90 percent of high-quality, plausibly causal studies found positive effects from additional K-12 spending.

However, Graff noted that the benefit “remained substantively quite modest in return for the cost.”

The authors of the meta-analysis concluded that an additional $1,000 per pupil per year generated about one-third of a percentile of additional growth in standardized test scores. For every $1,000 spent per pupil per year in 2018 dollars, schools produced outcomes equivalent to about five to six more days of learning.

Graff noted that means “general spending increases can work, albeit at a large cost for very modest improvements in test scores.”

High-quality research has also found that school-choice programs improve student achievement in public schools thanks to competitive effects.

Of 29 studies that examined the competitive effects of school choice, Graff noted 26 found positive effects, one found no effect, and only two contained any negative effects.

When Professor David Figlio and his co-authors studied Florida’s tax credit scholarship program from 2003 to 2017, a period in which the program grew from an initial enrollment of just over 15,000 students to nearly 110,000 by the 2017-18 school year, Graff noted the researchers found that public school outcomes increased significantly in areas where there was the most competition with private schools.

After fifteen years, students in schools with above-median competition were 120 days of learning ahead in reading, or two-thirds of a school year. Low-income public-school students were over 140 days of learning ahead after 12 years of competition with the tax credit program.

The cumulative cost of Florida’s tax credit scholarship program across the 15 years examined was $2.84 billion.

If that $2.84 billion had instead been spent on Florida’s public-school system, Graff found the impact on academic outcomes would have been far less than what was generated by the competitive impacts of the school-choice program.

“The school choice approach contributed to an additional 120 days of learning—or 2/3 of a school year more—in reading as compared to the 6 additional days of learning via the school spending approach for the same amount of total funding,” Graff wrote. “To achieve that same 120-day test score gain via the school spending approach, it would have cost Florida a total of $31.8 billion over that same fifteen years—more than an order of magnitude more expensive.”

When Florida is compared to other states, Graff noted that Florida “spends significantly less per-pupil and has increased its overall education spending much less than both the national average and no-choice states over the past twenty years.”

However, reading and math scores from the 2024 National Assessment of Educational Progress (NAEP) tests (adjusted for between-state student demographic differences) show that Florida’s fourth- and eighth-grade students are outperforming both the national average and states with no school choice programs, Graff noted.

“Even with half a million students enrolled across several distinct private school choice programs, Florida’s public-school students continue to outperform states with no private school choice while spending significantly less,” Graff wrote. “Florida’s experience suggests that states without private school choice—including teacher union strongholds like New York, New Jersey, Illinois, Oregon, and my native California—are missing out on a remarkably cost-effective method of academic improvement.”

Total Oklahoma public-school revenue from all sources—including local, state, and federal funds—has surged more than $3 billion since 2018, rising from $6.3 billion to $9.5 billion.

However, academic outcomes have steadily declined in Oklahoma public schools even as funding increased.

At the same time, the Oklahoma Parental Choice Tax Credit program involves a current maximum of $250 million in credits per year.

According to the most recent report from the Oklahoma Tax Commission, 39,604 children are attending private school this year thanks to the school-choice program, with 56 percent from low-income or middle-class families.

More than $247.9 million in credits have been claimed for the current school year. If demand exceeds the supply of credits next year, as is expected based on current trends, some Oklahoma families will be turned away.

Lawmakers are considering legislation that would raise the program cap to ensure no Oklahoma children are denied opportunity.

House Bill 3705, by state Rep. Chad Caldwell, and Senate Bill 1389, by state Sen. Julie Daniels, both increase the cap.

In his study, Graff indicated that increased funding for programs like the Oklahoma Parental Choice Tax Credit should be viewed as an indirect boost to public school students as well as a way to help children access private schools.

Graff wrote that the “effects of competition created a return on investment an order of magnitude larger than simply spending more.”

“Policymakers in states considering how to effectively allocate education dollars should view school choice not only as a way to create options for students who need them, but also as a system-level intervention which improves outcomes for all students across the state,” Graff wrote.