NCPA - National Center for Policy Analysis

Do Schools Begin Too Early?

May 18, 2012

School start times vary considerably, both across the nation and within individual communities, with some schools beginning earlier than 7:30 a.m. and others after 9:00 a.m.  Though staggering start times can reduce bus transportation costs, a coinciding negative impact on academic performance may outweigh this benefit.

Proponents of later start times, who have received considerable media attention in recent years, argue that many students who have to wake up early for school do not get enough sleep, and that beginning the school day at a later time would boost their achievement.  Finley Edwards of Colby College uses data from data from Wake County, North Carolina, to investigate this claim.

  • Comparing students with similar characteristics who attend schools that are similar except for having different start times, Edwards found that a one-hour delay in start time increases standardized test scores on both math and reading tests by roughly 3 percentile points.
  • Using an alternative method in which he followed the same schools over time as they change their start times, Edwards then measured a 2.2-percentile-point improvement in math scores and a 1.5-point improvement in reading scores associated with a one-hour change in start time.
  • Finally, using only data from students who experience a change in start time while remaining in the same school, Edwards measured increases of 1.8 percentile points in math and 1.0 point in reading for a one-hour later start time.

This final finding is the most crucial, as it eliminates nearly all conceivable forms of bias.  Furthermore, the increases were widespread enough that they are statistically significant increases, lending credence to proponents of later start times.

Furthermore, perhaps most crucial in this analysis is that disproportionate gains were seen among low-achieving students, suggesting that later start times would help close achievement gaps.

  • While the effect of a one-hour later start time on math scores may seem small, it is roughly 14 percent of the black-white test score gap.
  • Furthermore, it is 40 percent of the gap between those eligible and those not eligible for free or reduced-price lunch, and 85 percent of the gain associated with an additional year of parents' education.
  • These benefits of a later start time in middle school appear to persist through at least the 10th grade.

Source: Finley Edwards, "Do Schools Begin Too Early?" Education Next, Summer 2012.

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