California’s bold move to mandate later start times for middle and high schools could produce ripple effects far beyond the state, even as it’s yet to be seen whether pushing back start times on such a large scale will deliver major benefits for teenagers and for schools.
While health experts generally agree that getting adequate amounts of sleep is crucial to teens’ still-developing brains, the research on whether starting school later actually translates into more sleep—and better academic performance—is far from settled. But there may be further-reaching benefits beyond higher test scores. While school administrators have generally balked at the costs associated with starting school later, one recent study estimates that doing so across the country could add billions of dollars to the economy.
Under California’s new law, middle schools can’t start classes until 8 a.m. and high school until 8:30. Some rural schools are exempted.
Schools have three years to make the changes.
Downsides of not enough sleep
The American Academy of Pediatrics, the American Medical Association, the American Academy of Sleep Medicine, and the Centers for Disease Control and Prevention all recommend that school not start before 8:30 for middle and high school students—which is more in sync with the natural sleep patterns of those age groups.
Inadequate sleep can lead not just to academic problems in teens and pre-teens, it also contributes to obesity, depression, and an increased risk of car accidents, according to the American Academy of Pediatrics.
Some experts have proposed even more dramatic scheduling shifts. Researchers from Oxford University, Harvard University, and the University of Nebraska said 16-year-olds should not start school before 10 a.m., and 18-year-olds before 11 a.m.
One study from 2016 even found that adjusting start times (and sleep schedules) could help close academic performance gaps between boys and girls.
But while there is broad consensus among health experts that teens need more sleep and that their circadian rhythms naturally shift around puberty, the tangible academic benefits for districts that have taken this step are less clear, said Deborah Temkin, the senior director of education research at Child Trends.
California’s new policy will give researchers a rich opportunity to study the effects of later start times on a much larger scale.
“Very few studies have actually followed schools a year or so after a start time has changed,” Temkin said. “I think that’s really important to note that we don’t know what the sustainability of the gains is.”
That’s important, said Temkin, when weighing the benefits of later start times that may only give students 15 to 30 minutes extra sleep with the costs of say, purchasing additional buses to accommodate shifting schedules.
While students who start school later do tend to get more sleep—at least at first—how much, exactly, varies depending on the study, she said.
Much of the research on delayed school start times so far, she said, shows little to no academic benefit for students. That may be in part because students don’t necessarily continue going to bed at the same time just because school start times are pushed back.
It may also take a while for the benefits of extra sleep—such as improved health and academic achievement—to materialize.
Benefits of later start times
In general, Temkin said, there is a 50 percent return in pushing back a start time. For example, if a school starts 30 minutes later, students get an additional 15 minutes of sleep.
But even if teens aren’t getting tons more sleep, simply aligning school start times with their body clocks brings some benefits: The quality of the sleep they are getting in the morning is better than what they get later at night.
“Many sleep scientists really do see a benefit in that, it’s important to note,” she said. “There is the issue of sleep quality, but it doesn’t always make up for lack of sleep duration, the two go hand in hand.”
One unexpected benefit Temkin found in her own research is that parents were more likely to be home when their children got home from school under a shifted schedule that has students leaving school later, which meant less unsupervised time for students to engage in risky behavior such as drug use.
While early start times are disruptive to teens’ sleep, starting later can be hugely disruptive to districts and communities. That’s why adopting these policies can be so controversial—as they have been in California.
Delaying start times requires overhauling bus schedules and even, potentially, adding new buses to a district’s fleet. It can impact after-school activities and sports practices, costing districts extra money to keep the lights on.
It can affect traffic as parents drop their students off at later times.
And simply because school starts later doesn’t mean that all families can shift their schedules accordingly if parents or younger siblings have to start work and school earlier.
Higher graduation rates?
But some research shows there are also potentially significant benefits to reap in the long run and that focusing on immediate costs misses the big-picture gains.
One study from the RAND Corporation estimated the economic impact of pushing back start times to 8:30 a.m. on a state by state basis, and found that most states would recoup the money spent on adopting new start times in about two years.
The economic boosts would come from increased graduation rates which lead to higher lifetime earnings and fewer car crashes, according to the RAND research.
Research has found that well-rested teens have higher graduation rates, said Wendy Troxel, senior behavioral and social scientist at the RAND Corporation, in part because they have better attendance.
Drowsy driving is also major contributor to automobile accidents involving teens.
“In California specifically we found that two years after such a change in start times, California’s economy would grow by about $1.1 billion,” said Troxel.
While the costs associated with changing school start times is often a non-starter for many districts, she said, that’s only looking at one side of the equation.
“There are significant costs for maintaining the status quo,” she said.
