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How Does Public Environmental Information Shape Demand for Mitigation and Individual Exposure Assessment: A Survey Experiment on Water Lead (Pb) Exposure

Last registered on March 20, 2026

Pre-Trial

Trial Information

General Information

Title
How Does Public Environmental Information Shape Demand for Mitigation and Individual Exposure Assessment: A Survey Experiment on Water Lead (Pb) Exposure
RCT ID
AEARCTR-0016286
Initial registration date
August 05, 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
August 08, 2025, 7:15 AM EDT

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

Last updated
March 20, 2026, 2:15 PM EDT

Last updated is the most recent time when changes to the trial's registration were published.

Locations

Region

Primary Investigator

Affiliation
Columbia University

Other Primary Investigator(s)

PI Affiliation
University of Wisconsin-Madison

Additional Trial Information

Status
Completed
Start date
2025-09-03
End date
2025-10-31
Secondary IDs
Prior work
This trial is based on or builds upon one or more prior RCTs.
Abstract
Lead exposure from drinking water remains a critical public health concern in the U.S., primarily driven by lead service lines (LSLs)—lead pipes connecting water mains to buildings. Because LSL inventories offer only a proxy for household-level exposure, as tap water lead levels vary with pipe condition and corrosion control, we are motivated to investigate the following three questions. (1) How does receiving public information that serves as a proxy for pollution exposure affect individuals’ beliefs about personal exposure and confidence in those beliefs?
(2) How does it affect willingness to pay (WTP) for mitigation measures? (3) How does it affect WTP for individualized exposure assessments?
Leveraging the newly released LSL inventories, we conduct a survey experiment to study how receiving LSL information shapes perception of exposure and demand for mitigation and individualized exposure assessment. Survey participants are randomly assigned to receive either general EPA information (control) or additional information on whether their residential building has an LSL (treatment). Participants in the treatment arm are explicitly told that the LSL information is extracted from a city government database. The study measures key outcomes before and after the intervention: beliefs about LSL presence in their residential building, beliefs about tap water lead levels, confidence in these beliefs, WTP for lead-filtering pitchers, WTP for professional tap water lead testing, and WTP for pipe replacement.
External Link(s)

Registration Citation

Citation
Hu, Siyuan and Fanyu Wang. 2026. " How Does Public Environmental Information Shape Demand for Mitigation and Individual Exposure Assessment: A Survey Experiment on Water Lead (Pb) Exposure." AEA RCT Registry. March 20. https://doi.org/10.1257/rct.16286-1.2
Experimental Details

Interventions

Intervention(s)
Leveraging the newly released building-specific water service line datasets, this study will conduct an information provision experiment in several populated cities with prevalence of LSLs in the Midwest and the Northeast, using an online survey

In the information intervention, the control group will receive general information about the EPA’s requirement for public water systems to notify customers about LSLs. The treatment group will receive the same general information, plus building-specific details about whether their home’s service line is made of lead, retrieved from the city’s official inventory.
Intervention Start Date
2025-09-03
Intervention End Date
2025-10-31

Primary Outcomes

Primary Outcomes (end points)
The study measures key outcomes before and after the intervention: beliefs about LSL presence in their residential building, beliefs about tap water lead levels, confidence in these beliefs, WTP for lead-filtering pitchers, WTP for professional tap water lead testing, and WTP for pipe replacement. The first two WTPs are elicited using an incentive-compatible mechanism based on Becker et al. (1964).
Primary Outcomes (explanation)

Secondary Outcomes

Secondary Outcomes (end points)
Secondary Outcomes (explanation)

Experimental Design

Experimental Design
Participants will be screened and assigned a water service line material type through a geospatial matching process. The treatment group will be provided with information on whether their building's service lines are made of lead. Both the treatment and control groups will answer questions about their beliefs regarding whether their homes have LSLs, the safety level of the tap water, their WTP for water filters, and their WTP for kitchen tap water lead concentration inspections.
Experimental Design Details
Not available
Randomization Method
Randomization done through Qualtrics randomizer.
Randomization Unit
Individual respondents of the survey.
Was the treatment clustered?
No

Experiment Characteristics

Sample size: planned number of clusters
1500 respondent
Sample size: planned number of observations
1500 respondent
Sample size (or number of clusters) by treatment arms
750 respondents control, 750 respondents treatment
Minimum detectable effect size for main outcomes (accounting for sample design and clustering)
IRB

Institutional Review Boards (IRBs)

IRB Name
Minimal Risk Research IRB
IRB Approval Date
2025-08-05
IRB Approval Number
2025-0985-CP001
Analysis Plan

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