Sending your kids to school late pays off.

Delaying school start times nationwide to 8:30 a.m. could contribute $83 billion to the U.S. economy within a decade, and almost $9 billion in two years, a new study by the RAND Corporation and RAND EUROPE suggests.

The increases would come from long term effects, like better high-school graduation rates by 13.3%, and a 9.6% college attendance rate, which would outweigh the short-term costs to start school later per student by rescheduling bus routes for transportation.

It’s recommended that teens get an average of 8 to 10 hours of sleep each night, but up to 60% of middle school and high school students report getting less than seven hours on weeknights. That’s because when kids start going through puberty, their brains begin producing the sleep-inducing hormone melatonin on a delayed schedule, making it harder for them to get tired before 11 p.m. So a teen who goes to bed at 11 p.m. would need to sleep until at least 7:30 a.m. or later to get proper rest.

Not enough sleep is linked to childhood obesity, an annual cost of $45 billion. And teens who don’t get enough shut-eye are more likely to commit violent crimes which cost billions annually, according to the report.

Previous studies have suggested that going to school later could benefit kids and teens who scientists say are wired to stay up late. Not getting enough sleep can affect their health and academic performance, according to the American Academy of Sleep Medicine. Starting school no earlier than 8:30 a.m. will allow students to be more focused during the day, more alert while driving, and less likely to be late or absent from school.

In 2014, around 93% of high schools and 83% of middle schools in the US started before 8:30 a.m., according to the CDC, and more recently, some school districts have pushed back. Last year, Dobbs Ferry School District in Westchester County, New York started pushing back their middle and high school start times a half hour later from its original 8:15 a.m. for middle school and 7:30 a.m. for high schoolers in an effort to combat sleep deprivation and increase focus. The schools reported major benefits after the time change, like kids being able to actually have time to eat breakfast.