Reducing Indoor Air Pollution

Last registered on August 09, 2022


Trial Information

General Information

Reducing Indoor Air Pollution
Initial registration date
August 09, 2022

Initial registration date is when the trial was registered.

It corresponds to when the registration was submitted to the Registry to be reviewed for publication.

First published
August 09, 2022, 5:02 PM EDT

First published corresponds to when the trial was first made public on the Registry after being reviewed.


Primary Investigator

University of Southern California

Other Primary Investigator(s)

PI Affiliation
London School of Economics

Additional Trial Information

On going
Start date
End date
Secondary IDs
Prior work
This trial does not extend or rely on any prior RCTs.
The adverse impacts of ambient air pollution and its associated costs have received substantial policy and academic attention. However, the issue of indoor air pollution is often overlooked in academic research and policy discussions, which is surprising given the fact that
individuals in the developed world spend almost 90 percent of their time indoors. Therefore, the potential welfare implications from exposure to indoor air pollution could be very large.

We have designed a field experiment that will explore how access to personalized, real-time indoor air pollution monitoring and information affects individuals’ behavior in reducing their indoor air pollution levels. To investigate this, we will implement the field experiment in London.

We will also ascertain people's demand and welfare benefits from such monitoring, information, education, and clean indoor air. If the provision of monitoring and information is found to reduce exposure to air pollution and deliver positive health outcomes, indoor air pollution monitoring could be scaled up and combined with other targeted public health campaigns to reduce exposure to harmful pollutants.
External Link(s)

Registration Citation

Metcalfe, Robert and Sefi Roth. 2022. "Reducing Indoor Air Pollution." AEA RCT Registry. August 09.
Experimental Details


We will estimate the impact of personalized air pollution monitoring and information on indoor air quality, health, and well-being.

This project would seek to investigate how such real-time personalized indoor air pollution monitoring can inspire behavioral changes that improve indoor air quality, and thus overall health and well-being in the context of London.
Intervention Start Date
Intervention End Date

Primary Outcomes

Primary Outcomes (end points)
Pollution Exposure
Behavioral Change
Health and Well-being Outcomes
Willingness to Pay for Air Monitor and Air Purifier
Primary Outcomes (explanation)

Secondary Outcomes

Secondary Outcomes (end points)
Beliefs about Indoor Air Pollution
Secondary Outcomes (explanation)

Experimental Design

Experimental Design
Control: Monitor indoor air pollution

Treatment: Monitor indoor air pollution and provide real time feedback on the indoor air pollution.
Experimental Design Details
The primary objective of this research is to explore how access to personalized, real-time air pollution monitoring and information affects individuals’ behavior in reducing their indoor air pollution levels. To investigate this, we will design a field experiment in London.

Of those samples, we will randomize residents into three groups:

1. Control group:

They will receive a Kaiterra air pollution monitor. This monitor collects real-time information about indoor air pollution levels and feeds it into an online database. A security sticker will be placed on the monitors to prevent residents from viewing their air pollution reading. We will know whether the security sticker has been tampered with—we had 100% compliance with this issue in the
pilot study.

2. Treatment group: Personalized information.

They will have the same experience as the control group, but the security sticker will be removed after two weeks (to get baseline data).
Subsequently, they will be given basic information on the health effects of PM2.5 and what they can do to reduce air pollution in their homes. We will monitor PM2.5 levels for four weeks after the sticker has been removed.

Before the experiment, participants will be asked to complete an online survey about their perceived air pollution levels, demographic characteristics, dwelling characteristics, and baseline health and wellbeing.

This information will also be used to conduct a stratified randomization. Additionally, participants will be asked to complete a second survey at the end of the experiment, focused on the experience itself (e.g., what behaviors were changed) as well as a health and well-being assessment.

These questions allow us to understand the mechanisms/margins of adjustment and also their health and well-being implications.

The survey will also include a question about participants’ incentive-compatible willingness to pay for their own air pollution monitor or an air purifier, should they win a voucher for $150. At the end of the research project, participants will receive a debriefing information sheet as well as a $20 voucher to compensate them for participating in the experiment.
Randomization Method
Stratified randomization based on beliefs about air quality. Balanced on all other variables in the survey.
Randomization Unit
Was the treatment clustered?

Experiment Characteristics

Sample size: planned number of clusters
Sample size: planned number of observations
150 individual households.
Sample size (or number of clusters) by treatment arms
75 households in each experimental condition.
Minimum detectable effect size for main outcomes (accounting for sample design and clustering)

Institutional Review Boards (IRBs)

IRB Name
London School of Economics
IRB Approval Date
IRB Approval Number


Post Trial Information

Study Withdrawal

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Is the intervention completed?
Data Collection Complete
Data Publication

Data Publication

Is public data available?

Program Files

Program Files
Reports, Papers & Other Materials

Relevant Paper(s)

Reports & Other Materials