Air Quality, Economic Opportunity, and Affordable Housing

Last registered on March 26, 2025

Pre-Trial

Trial Information

General Information

Title
Air Quality, Economic Opportunity, and Affordable Housing
RCT ID
AEARCTR-0015489
Initial registration date
March 18, 2025

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 26, 2025, 8:42 AM EDT

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

Locations

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Primary Investigator

Affiliation
University of California - Berkeley

Other Primary Investigator(s)

PI Affiliation
University of Texas - Austin
PI Affiliation
University of Virginia

Additional Trial Information

Status
On going
Start date
2024-07-15
End date
2026-03-31
Secondary IDs
Prior work
This trial does not extend or rely on any prior RCTs.
Abstract
This pre-analysis plan (PAP) outlines the design and intended analysis for a randomized controlled trial (RCT) conducted in partnership with AffordableHousing.com. The experiment aims to investigate how information frictions affect the housing choices of low-income individuals in the United States.

Registered users of AffordableHousing.com will be randomly assigned into three groups: 25% to an intervention providing detailed air quality information (an important input into health, human capital, and economic opportunity), 25% to an intervention providing information about the overall economic opportunity of the neighborhood (a summary measure reflecting the combined attributes of a neighborhood that shape
upward economic mobility), and 50% to a control group receiving no information. Additionally, we will survey a subset of users to assess their understanding of the air quality and economic mobility information, as well as their perceptions, attitudes, and beliefs about air quality and economic mobility. Within the survey, we randomize an additional information intervention emphasizing how air quality and economic mobility
are important for well-being.

The motivation for this study emerges from the empirical observation that low-income families in the United States disproportionately reside in neighborhoods associated with limited opportunities for economic advancement. While it is possible that these choices might reflect genuine preferences for affordability, proximity to employment, or family networks, an alternative explanation is that that information frictions or other barriers prevent these families from identifying and relocating to higher-opportunity neighborhoods. By explicitly randomizing information on air quality and economic mobility, our experiment will isolate the role that such informational barriers play in shaping location decisions.
External Link(s)

Registration Citation

Citation
Bergman, Peter, Jonathan Colmer and Ian Hardman. 2025. "Air Quality, Economic Opportunity, and Affordable Housing." AEA RCT Registry. March 26. https://doi.org/10.1257/rct.15489-1.0
Sponsors & Partners

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Experimental Details

Interventions

Intervention(s)
Registered users of AffordableHousing.com will be randomized into either of two treatment arms or a control group. The two treatment arms provide:
- Information about air quality in the Census Tract of each listing
- Information about economic mobility in the Census Tract of each listing

We will assign 25% of users to each of the treatment arms, and the remaining 50% to the control group.

When a user enters a search query (e.g. "Detroit, MI") into the search box on the AffordableHousing.com landing page, the website returns 1) a list of search results, i.e. listings, and 2) a map covering the geographic extent of the searched region, with pins highlighting the locations of the returned listings. All users see the same set of listings and same map extent; however, treated users will also be given information about air quality or economic mobility.
Intervention Start Date
2024-07-15
Intervention End Date
2025-03-31

Primary Outcomes

Primary Outcomes (end points)
Air Quality Intervention:
-Environment score where individual users live 12 months after randomization Or 6 months to 12 months after randomization if our data on where they live is captured less than one year after random assignment.
-Application rate for listings with worst environment score badge (score of 1).

Economic Mobility Intervention:
-Mobility score where individual users live 12 months after randomization Or 6 months to 12 months after randomization if our data on where they live is captured less than one year after random assignment.
-Application rate for listings with worst mobility score badge (score of 1).
Primary Outcomes (explanation)
This RCT’s goal is to test whether an information intervention changes the housing and location choices of AffordableHousing.com users. A primary short-run outcome of interest is to see if treated individuals apply end up living at a listing with significantly different air quality or economic mobility relative to the control group. We will analyze outcomes across several subgroups, as well. These include voucher holders, mobile users, those with rental applications, and parents.

Secondary Outcomes

Secondary Outcomes (end points)
-Number of rental applications for each label of the environment score
-Average environment score where users live 12 months and more after the intervention
-Average environment score of viewed/contacted/applied-to properties by week
-Number of rental applications for each label of the economic mobility score
-Average economic mobility score where users live 12 months and more after the intervention
-Average mobility score of viewed/contacted/applied-to properties by week
Secondary Outcomes (explanation)

Experimental Design

Experimental Design
To measure the effect of treatment on various outcomes, we estimate the following:

Y_i = β_0 + β_1 TREAT_i + X'_i γ+ ε_i

where Y_i is the outcome of interest for user i and β_1 is the coefficient of interest on the treatment variable.

If HUD data are available, covariates in X_i will include, total annual income, an indicator for whether the user’s housing voucher is from an authority with “Moving to Work” designation, indicators for race (white, black, and hispanic), indicators for users with children in the following groups: 0-4, 5-10, 11-14, and 14+, indicator for “Hard to House” status (as defined by HUD), and commuting zone fixed effects. HUD data may not be available to us, however, in which case our covariates will be voucher status, an indicator submitted rental app pre-treatment, has accessibility needs, intended move-in date, indicator for mobile/desktop browser, week fixed effects, missingness indicator + imputation for missing values Because people may visit the site with minimal engagement, we will also examine our results for the subgroup formed by restricting the sample to those who have a mobile/desktop indicator, indicating the user entered a search term and didn’t leave the site before ever searching for a property (and so seeing a treatment). Another subgroup is people with rental applications at baseline, we can also add: baseline tract atlas and pollution scores, age, reason for moving, income, employment, and whether they have children. Within this group, we will explore effects for those users with children.

We also collect information from two surveys given to AffordableHousing.com users: Air Quality Survey This survey was offered to 25,000 user accounts stratified by experimental treatment assignment. We describe the purpose of the survey as aiding researchers to “understand how people perceive and prioritize environmental factors, like air quality, when searching for housing.” This survey includes questions on the respondent’s background (gender, age, education, etc.), their reasons for moving, and their prior beliefs about air quality. We then provide an information intervention where we randomly provide the following information about the difference between high and low air quality areas in the US to some users:

"This is an equivalent to smoking 36 cigarettes a year. Breathing in fine particulate matter makes it harder for your body to get the oxygen it needs. Over time, this can lead to serious health problems, including heart issues and even damage to your brain. Studies show that even short exposure to these tiny particles can make you feel tired, make it harder to concentrate and think clearly, and, over time, increase the risk of diseases like Alzheimer’s and dementia."

Respondents are then asked to interpret air quality information provided via a chloropleth map and an informational badge. Economic Mobility Survey This survey was offered to 25,000 user accounts stratified by experimental treatment assignment. We describe the purpose of the survey as aiding researchers to “understand how people perceive and prioritize certain factors, when searching for housing.” This survey includes questions on the respondent’s background (gender, age, education, etc.), their reasons for moving, and their prior beliefs
about economic opportunity. We then provide an information intervention where we randomly provide the following information about the difference between high and low economic opportunity areas in the US to some uses.

"If a child moved at birth from the average low-economic mobility neighborhood (bottom 25% in the US) to the average high economic mobility neighborhood (top 25% in the US), the expected income of that child as an adult would increase by $17,000 per year”.

Respondents are then asked to interpret economic mobility information provided via a chloropleth map and an informational badge.
Experimental Design Details
Not available
Randomization Method
Randomization performed by trial partner (AffordableHousing.com). Users are randomized into treatment and control arms when they first navigate to the search results page on the website and regardless of whether they click on anything.
Randomization Unit
Individual user account registered with AffordableHousing.com
Was the treatment clustered?
No

Experiment Characteristics

Sample size: planned number of clusters
The total number of observations is anticipated to be around 200,000 user accounts. The exact number will depend
on how many people visit the website during the study period.
Sample size: planned number of observations
200,000 user accounts
Sample size (or number of clusters) by treatment arms
100,000 users control, 50,000 air quality intervention, 50,000 economic mobility intervention
Minimum detectable effect size for main outcomes (accounting for sample design and clustering)
IRB

Institutional Review Boards (IRBs)

IRB Name
University of Texas at Austin Social Behavioral and Educational Research IRB
IRB Approval Date
2024-11-20
IRB Approval Number
N/A
Analysis Plan

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