Learning is in the Air: Clean Air as an Experience Good

Last registered on March 06, 2024


Trial Information

General Information

Learning is in the Air: Clean Air as an Experience Good
Initial registration date
February 27, 2024

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
March 06, 2024, 3:33 PM EST

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



Primary Investigator

University of Chicago

Other Primary Investigator(s)

PI Affiliation
University of Chicago
PI Affiliation
Australian National University

Additional Trial Information

In development
Start date
End date
Secondary IDs
Prior work
This trial does not extend or rely on any prior RCTs.
Despite the enormous health costs of air pollution, willingness-to-pay (WTP) for clean air in highly polluted developing contexts remains very low. We posit that one significant and understudied reason is that clean air is an experience good, whose value is revealed after consumption. We employ a cluster-randomized trial to test this hypothesis. We seek to document the existence of an ``experience wedge", i.e. a difference between anticipated and realized utility of consuming a good. To do this, we deploy a novel experienced-based intervention, air quality monitors and purifiers, which may provide a more salient treatment than traditional information mediums, such as pamphlets or videos. To explore the mechanisms behind the experience wedge, we implement a purifier-only treatment arm to experimentally distinguish between (1) knowledge about objective pollution exposure and (2) the sensory experience of breathing in polluted air. This will be the first experimental evidence demonstrating how experience can shift demand for clean air, offering insights for public health policy and environmental awareness campaigns, while also highlighting the implications for using WTP estimates in economic evaluations.
External Link(s)

Registration Citation

[email protected], Budy, Jeanne Sorin and Yixin Sun. 2024. "Learning is in the Air: Clean Air as an Experience Good." AEA RCT Registry. March 06. https://doi.org/10.1257/rct.13110-1.0
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Experimental Details


We will provide (1) air quality monitor and purifier and (2) purifier-only to two treatment groups. Our control group will receive a fan that looks identical to a purifier.
Intervention Start Date
Intervention End Date

Primary Outcomes

Primary Outcomes (end points)
Indoor PM2.5 levels.

Demand for clean air, measured by (1) WTP for an air purifier rental, (2) pollution avoidance behavior index, (3) time spent indoors in purifier space, (4) demand for public action on clean air.

Beliefs: accuracy of perceived indoor and outdoor air pollution levels; beliefs about impact of air pollution on own and child's health; perceived effectiveness of air purifiers;

Health: biometrics (blood pressure and blood oxygen), self-reported measures of physical health, cognitive ability, sleep quality, and mental health.
Primary Outcomes (explanation)
A more detailed description of outcome variables will be provided in the pre-analysis plan.

Secondary Outcomes

Secondary Outcomes (end points)
Knowledge index
Secondary Outcomes (explanation)
We will also conduct heterogeneity on the following dimensions:
- Baseline beliefs about their household’s indoor air quality and beliefs about how indoor air pollution affects household health
- Baseline WTP for purifiers, measured by stated preferences
- Baseline food expenditure
- Baseline ambient air pollution levels
- Baseline self-reported health, as well as child’s health and health of any elderly family members that are residing in the home

Experimental Design

Experimental Design
We randomly sort participant households into three groups: a control group, a comprehensive experience treatment, and a sensory-based treatment. Our main treatment is the comprehensive experience treatment, where households receive an air purifier and air quality monitor for three months. This treatment targets two sources fueling the experience wedge: (1) \exposure wedge, or lack of knowledge on own objective exposure to pollution and (2) sensory wedge, lack of sensory experience with clean air and accompanying health and productivity benefits, leading to misperceptions of the marginal utility of clean indoor air.

Households in a secondary treatment receive only an air purifier but not the visible measurements provided by the monitor. This sensory-based treatment arm will dig into the mechanisms behind the experience wedge, with the aim of experimentally differentiating between the exposure wedge and the sensory wedge
Experimental Design Details
Not available
Randomization Method
Our sample will be parents of elementary school children. Our cluster-randomization will be at the school-level. We stratify randomization on the baseline average monthly expenditure and pollution of the area that the school is in. Randomization will be done by our research partner, SMERU, by a computer, before baseline.
Randomization Unit
Our cluster-randomization will be at the school-level.
Was the treatment clustered?

Experiment Characteristics

Sample size: planned number of clusters
180 schools
Sample size: planned number of observations
950 households
Sample size (or number of clusters) by treatment arms
60 schools for control and the two treatments.
Minimum detectable effect size for main outcomes (accounting for sample design and clustering)

Institutional Review Boards (IRBs)

IRB Name
University of Chicago
IRB Approval Date
IRB Approval Number
Analysis Plan

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