Sleepless in Chennai: The Consequences of Sleep Deprivation Among the Urban Poor
Last registered on June 05, 2021


Trial Information
General Information
Sleepless in Chennai: The Consequences of Sleep Deprivation Among the Urban Poor
Initial registration date
December 08, 2017
Last updated
June 05, 2021 3:41 PM EDT
Primary Investigator
Harvard University
Other Primary Investigator(s)
PI Affiliation
Massachusetts Institute of Technology
PI Affiliation
Harvard University
PI Affiliation
University of Pennsylvania
PI Affiliation
Massachusetts Institute of Technology
Additional Trial Information
Start date
End date
Secondary IDs
The urban poor in developing countries are tired: noise, heat, pain, and physical discomfort all interfere with their sleep. Low-income adults in Chennai, India, sleep on average just over five hours a night (based on our pilot studies). How does insufficient sleep affect how these individuals think, work, and make decisions? Can simple and scalable interventions improve sleep among the poor in a cost-effective way? We investigate these questions in a field experiment in Chennai. The randomized controlled trial aims to: (i) evaluate three interventions (devices to improve the home sleep environment; incentives to sleep more; naps at work) to improve sleep among the urban poor; (ii) estimate the causal impact of improved sleep on cognitive function, health, and economic outcomes.
External Link(s)
Registration Citation
Rao, Gautam et al. 2021. "Sleepless in Chennai: The Consequences of Sleep Deprivation Among the Urban Poor." AEA RCT Registry. June 05.
Former Citation
Rao, Gautam et al. 2021. "Sleepless in Chennai: The Consequences of Sleep Deprivation Among the Urban Poor." AEA RCT Registry. June 05.
Sponsors & Partners

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Experimental Details
Our treatment intervention is aimed at improving participants' sleep and includes the following components:

1) Participants assigned to the "sleep treatment" group (further details in the experimental design section) receive sleep aids and encouragement to sleep more. Sleep aids include pillows, mattresses, fans, blankets, bedsheets, cots, earplugs, and eyeshades; participants may choose to bring some or all of these devices home with them for the duration of the treatment period.

2) Participants assigned to the "sleep treatment + incentives" group are exposed to the same intervention as those in the "sleep treatment" group and are also financially incentivized to sleep more; these participants are paid for the amount that they sleep beyond a given benchmark.

3) Participants assigned to the "nap treatment" are provided the opportunity to take a half-hour afternoon nap in a comfortable and save environment in the lab.
Intervention Start Date
Intervention End Date
Primary Outcomes
Primary Outcomes (end points)
Sleep duration (our first stage outcome); productivity, labor supply, and earnings in our data entry task; decision making outcomes (specifically, performance on risk and social preferences tasks, susceptibility to defaults and salience effects, savings decisions, and performance on a task measuring present bias); and performance on the psychomotor vigilance task (a proxy for sleep deprivation). Details are provided in the pre-analysis plan.
Primary Outcomes (explanation)
Secondary Outcomes
Secondary Outcomes (end points)
Cognitive function (performance on Hearts and Flowers and Corsi lab tasks); subjective wellbeing; quantity and quality outcomes in the data entry task. We will also collect data on health outcomes (blood pressure, depression and others), which are described in our registration at with the title "Chronic Sleep Deprivation Among the Poor: A Lab-in-the-Field Approach"
Secondary Outcomes (explanation)
Experimental Design
Experimental Design
The proposed RCT involves 450 participants recruited to work full-time for 28 business days in a data-entry job. After an eight-day baseline period, participants are randomized into the following three groups, with an equal number of participants in each group:

(1) Control Group: Participants in the control group continue to work in our lab office but do not receive the interventions described above;

(2) Sleep Treatment: Participants in the sleep treatment group receive sleep aid devices (mattresses, ear plugs, etc) as well as daily encouragement to sleep more;

(3) Sleep Treatment + Incentives: Participants in the sleep treatment + incentives group are exposed to the same interventions as participants in the sleep treatment but are also receive a daily financial incentive based on how much they increased their sleep over a given benchmark.

Each of the above three groups is cross-randomized (50-50) with a "nap treatment". The nap treatment group will be assigned to take a half-hour nap each afternoon. Those not receiving the nap treatment will be randomized into either taking a break or working during the same time slot.
Experimental Design Details
Randomization Method
The randomization of participants to treatment groups will be performed by a computer and will by stratified along baseline sleep and productivity.
Randomization Unit
The randomization is performed at the individual level.
Was the treatment clustered?
Experiment Characteristics
Sample size: planned number of clusters
Sample size: planned number of observations
450 participants
Sample size (or number of clusters) by treatment arms
1/3 of the 450 participants are assigned to each our three sleep treatment arms: 150 control participants; 150 sleep treatment participants; 150 sleep treatment + incentives participants.

1/2 of the 450 participants are assigned to our nap treatment: 225 nap treatment participants.
Minimum detectable effect size for main outcomes (accounting for sample design and clustering)
Our MDE is .13 hours, or 7.8 minutes, of additional sleep per night. This represents an approximately 2.4% increase over baseline sleep levels.
IRB Name
Harvard University Human Research Protection Program
IRB Approval Date
IRB Approval Number
IRB Name
Institute of Financial Management and Research, India
IRB Approval Date
IRB Approval Number
"Chronic Sleep Deprivation Among the Poor: A Lab-in-the-field Approach"
Analysis Plan
Analysis Plan Documents
Pre-Analysis Plan

MD5: 8666d6d01136b3d4d60b21210fdc5b75

SHA1: 4706231dfb8d88a80eb45e8cd0553cf3c6b6bb59

Uploaded At: December 08, 2017

Post Trial Information
Study Withdrawal
Is the intervention completed?
Intervention Completion Date
April 23, 2019, 12:00 AM +00:00
Is data collection complete?
Data Collection Completion Date
April 23, 2019, 12:00 AM +00:00
Final Sample Size: Number of Clusters (Unit of Randomization)
452 participants
Was attrition correlated with treatment status?
Final Sample Size: Total Number of Observations
8,454 participant-nights
Final Sample Size (or Number of Clusters) by Treatment Arms
Control - 152, Devices + Encouragement - 150, Devices + Incentives - 150
Data Publication
Data Publication
Is public data available?
Program Files
Program Files
Reports, Papers & Other Materials
Relevant Paper(s)
The urban poor in developing countries face challenging living environments, which may interfere with good sleep. Using actigraphy to measure sleep objectively, we find that low-income adults in Chennai, India, sleep only 5.5 hours a 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 a night by inducing more time in bed. Contrary to expert predictions and a large body of sleep research, increased nighttime sleep had no detectable effects on cognition, productivity, decision making, or well being, and led to small decreases in labor supply. In contrast, 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 cognition, but a decrease in work time.
Pedro Bessone, Gautam Rao, Frank Schilbach, Heather Schofield, Mattie Toma, The Economic Consequences of Increasing Sleep Among the Urban Poor, The Quarterly Journal of Economics, 2021;, qjab013,