| Abstract: |
There is growing evidence on the importance of sleep for productivity, but
little is known about the impact of interventions targeting sleep. In a field
experiment among U.S. university students, we show that incentives for sleep
increase both sleep and academic performance. Motivated by theories of
cue-based habit formation, our primary intervention couples personalized
bedtime reminders with morning feedback and immediate rewards for sleeping at
least seven hours on weeknights. The intervention increases the share of
nights with at least seven hours of sleep by 26 percent and average weeknight
sleep by an estimated 19 minutes during a four-week treatment period, with
persistent effects of about eight minutes per night during a one to five-week
post-treatment period. Comparisons to secondary treatments show that immediate
incentives have larger impacts on sleep than delayed incentives or reminders
and feedback alone during the treatment period, but do not have statistically
distinguishable impacts on longer-term sleep habits in the post-treatment
period. We estimate that immediate incentives improve average semester course
performance by 0.075--0.088 grade points, a 0.10--0.11 standard deviation
increase. Our results demonstrate that incentives to sleep can be a
cost-effective tool for improving educational outcomes. |