Scott Walker wants to let schools cut down on class time. That’s really risky.

Wisconsin Gov. Scott Walker doesn’t seem to care how many hours schoolkids are in the classroom, as long as they can pass standardized tests — a proposal that could go against the academic consensus that time in the classroom matters.

In his recent budget proposal, Walker called for state lawmakers to get rid of the minimum requirement for how many hours students spend learning each year. That would make Wisconsin the first state without any guidelines for how long students must spend in the classroom. Typically, states require at least 180 school days, and Wisconsin law currently requires 1,050 instructional hours for elementary school students at public and private voucher schools and at least 1,137 for middle and high school students.

Walker says the requirement is an unnecessary regulation. Instead, the best way to measure school performance, he says, is through the annual report card put together by Wisconsin’s Department of Public Instruction, based largely on standardized test scores. “For us, it’s about eliminating the mandate,” he told the Milwaukee Journal Sentinel. “I want to give maximum flexibility to districts.”

“Flexibility” is a key word in this proposal. Ultimately, the move is part of a bigger Republican push to deregulate education — an agenda Secretary of Education Betsy DeVos and President Donald Trump have both endorsed. Walker’s argument is that without school hour mandates, school districts will have more freedom to innovate or invest in virtual learning.

But there are a lot of unknowns with this proposal — and several strong counterarguments.

“There just isn’t enough evidence on things like blended and online learning yet that would inform schools how to use that flexibility to increase student learning,” Seth Gershenson, an education policy expert at American University, said, adding that there is a solid amount of research that shows students who spend more time in the classroom end up learning more, especially in math.

And for schools already struggling to keep doors open, this proposal would give administrators the option to cut hours, which could limit the success of lower-income children.

Classroom time is not a priority for Walker. “To me, the report card is the ultimate measure. It’s not how many hours you are sitting in a chair,” the governor said during a school visit in Waukesha. In other words, he wants to focus on outcomes rather than input.

But educational research has found that the number of hours in the classroom matters. “I think it’s a bit counterintuitive based on research we know on instructional time,” Julie Mead, an education policy professor at University of Wisconsin Madison, said. “In these budgetary times, those districts without the means could cut instructional time, which would exacerbate the differences between the haves and the have-nots.”

Wisconsin public schools have been dealing with massive state budget cuts for the greater part of Walker’s tenure, after he slashed $782 million from public education funding in 2012, hiking up teachers’ pension and health care costs. This latest budget proposal is an attempt to reverse course, calling for a record level of K-12 funding, but nevertheless the policy change could put instructional hours on the chopping block for struggling schools.

Studies have overwhelmingly found that on average, students benefit from more time in the classroom — not less. At the Brookings Institution, Gershenson summarized some of the findings, based on surveys of kindergartners and school districts that experienced more snow days:

Students who experienced more school days between the fall and spring tests made significantly larger achievement gains than their peers who experienced fewer schools days between tests [...]

An additional month of schooling would increase the average student’s achievement by 12 to 15 percent of a test score [standard deviation], which is similar in magnitude to the impacts of other potential education interventions.

In other words, the longer students spent learning, the more progress they made between the beginning and end of the year.

These findings are consistent with pilot programs in various states that saw longer instructional days actually helped improve academic achievement in struggling public schools. A 2011 study of charter schools in New York found that high-achieving charter schools required their students to spend significantly more time in class — including longer days and years — compared with more typical charter schools that didn’t get those results. A similar study in 2009 found that the longer school year was one of the key factors in high-achieving charter schools’ success.

The extended-school-day programs even caught the eye of former President Barack Obama, who, as the Washington Post noted, advocated for extending school time in 2009:

Our children — listen to this — our children spend over a month less in school than children in South Korea — every year. That’s no way to prepare them for a 21st century economy. That’s why I’m calling for us … to rethink the school day to incorporate more time -— whether during the summer or through expanded-day programs for children who need it.

Wisconsin’s DPI agrees, according to WISN, an ABC News affiliate: “A spokesperson with the state Department of Public Instruction said the agency has no official position on the governor’s plan but said that overall, students need more access to learning, not less.” Walker’s plan, though, would do the opposite.