One-third of our time is dedicated to sleep, yet little is known about the levels and consequences of sleep deprivation, especially in the developing world. To begin to address this gap, this paper measures the prevalence and consequences of sleep deprivation among the urban poor in India via an RCT.
We find that low-income adults in Chennai sleep little and poorly—5.6 hours of objectively-measured sleep per night—despite 8 hours in bed. Their sleep can be increased substantially: randomized treatments providing simple devices, encouragement, (and for some) financial incentives increase night sleep by over 30 minutes. Offering short naps at the workplace in the afternoon also increased daily sleep.
However, increased night sleep had no detectable effects on cognition, productivity, economic decision-making, or physical health, and led to small decreases in labor supply. In contrast, naps improved cognition, subjective well-being, and labor productivity. Naps also reduced attention to incentives and present bias, and increased financial savings.
Our results provide a possible explanation for the persistence of widespread sleep deprivation and the relatively high prevalence of afternoon naps in many developing countries. This project is joint with Pedro Bessone, Gautam Rao, Frank Schilbach, and Mattie Toma.
Using state-of-the-art technology, we document that adults in Chennai sleep only 5.5 hours per night on average despite spending 8 hours in bed. Their sleep is highly interrupted, with sleep efficiency—sleep per time in bed—comparable to those with disorders such as sleep apnea or insomnia.
A randomized three-week treatment providing information, encouragement, and improvements to home sleep environments increased sleep duration by 27 minutes per night but came at the cost of more time in bed.
Contrary to expert predictions, increased night sleep had no detectable effects on cognition, productivity, decision-making or well-being, and led to small decreases in labor supply.
Yet, increased sleep can have benefits in this setting: short afternoon naps at the workplace improved an overall index of outcomes by 0.12 standard deviations, with significant increases in productivity, psychological well-being, and cognitive function, but less time available for work.