Early high school start times adversely affect attendance

"The American Academy of Pediatrics recommends that high schools begin class after 8:30 a.m., but we know that most schools start much earlier," says Melinda Morrill, an associate professor of economics at North Carolina State University and corresponding author of a paper on the work. "We were able to look at five high schools that moved start times from 8:05 a.m. to 7:25 a.m. in order to examine the effect that the change had on students."

The researchers looked at data on seven cohorts of students, with graduation years ranging from 2013 to 2019. Specifically, researchers looked at data from the freshman, sophomore and junior years of each cohort. The change in start times was implemented in the 2012-13 school year. As an additional control group, the researchers also looked at data from 14 other high schools in the same school district that had already adopted a 7:25 a.m. start time.

"There's a growing body of research that suggests earlier start times can hurt test scores," Morrill says. "We looked at that, but the numbers weren't statistically significant one way or the other."

"However, the move to the earlier start times caused a small increase in the number of students who did not advance to 12th grade on time," says John Westall, a Ph.D. candidate at NC State and co-author of the paper. "Specifically, the move from 8:05 to 7:25 was associated with students being 8% more likely not to advance to 12th grade on schedule."

"We also wanted to look beyond testing to see if there were effects on other measures of academic engagement," Morrill says. "And we found a significant increase in both absences and tardiness."

"The change to an earlier start time led to an increase of about one additional absence per year and just over three additional tardy arrivals per year for students," Westall says. "So students were definitely missing more school."

"Looking at all 19 of the schools, we found that historically, the five schools that started at 8:05 had significantly lower rates of absenteeism and tardiness than the 14 schools that started at 7:25," Morrill says. "But once those five schools moved their start time to 7:25, those advantages disappeared.

"The take-home message here is that we need to look at more than just test scores if we want to understand all of the ways that early start times can affect high school students," Morrill says. "We know that school districts have to consider a wide range of issues, such as transportation logistics, student safety, extracurricular activities and school finances. But the more we look, the more the findings suggest that there are significant consequences of early start times for students."