The impact of personalized information on individual decisions to mitigate forever chemicals: Evidence from an online randomized evaluation

Last registered on February 19, 2025

Pre-Trial

General Information

Title

RCT ID

AEARCTR-0014470

Initial registration date

February 12, 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

February 19, 2025, 8:53 AM EST

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

Locations

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Primary Investigator

Name

Sonia Refulio-Coronado

Affiliation

University of Rhode Island

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Other Primary Investigator(s)

PI Name

Emi Uchida

PI Affiliation

University of Rhode Island

Contact Investigator

PI Name

Kent Messer

PI Affiliation

University of Delaware

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PI Name

Caroline Noblet

PI Affiliation

University of Maine

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Additional Trial Information

Status

On going

Start date

2024-09-09

End date

2025-03-31

Keywords

Behavior, Environment & Energy, Other

Additional Keywords

PFAS, drinking water, filters

JEL code(s)

Q25, Q52, Q53

Secondary IDs

Prior work

This trial is based on or builds upon one or more prior RCTs.

Abstract

Adopting technologies to mitigate pollution exposure, such as water filters certified to remove PFAS, requires individuals to overcome significant knowledge and decision-making barriers. These include search costs, misinformation, and the challenge of connecting current adoption decisions with uncertain future health benefits. In behavioral science, information programs tailored to specific consumers have been effective across multiple domains. These programs intend to shape individual behavior in a manner considered welfare-improving from the perspective of society and the individual. However, to date, tailored messaging has not been tested for consumers’ decisions in pollution aversion behavior.

This study uses an online randomized experiment to evaluate the impact of personalized information on consumer adoption of water filters certified to remove PFAS. Participants are randomly assigned to one of three groups: a control group with no information, treatment group 1 receiving generic information about PFAS, or treatment group 2 receiving both generic and personalized information tailored to household composition and medical history. The survey assesses participants' water usage behaviors, PFAS knowledge, and willingness to purchase a certified water filter, with follow-up data collected to measure changes over time.

The experiment plans to recruit 1,500 participants from a nationally representative sample, supplemented by 350 participants from Rhode Island, Delaware, and Maine, and a pretest of 300 participants. Results will provide insights into the role of tailored messaging in reducing knowledge barriers and encouraging the adoption of health-protective technologies. This research offers evidence to inform policies promoting equitable engagement in pollution aversion behaviors.

External Link(s)

Registration Citation

Citation

Messer, Kent et al. 2025. "The impact of personalized information on individual decisions to mitigate forever chemicals: Evidence from an online randomized evaluation." AEA RCT Registry. February 19. https://doi.org/10.1257/rct.14470-1.0

Sponsors & Partners

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Experimental Details

Interventions

Intervention(s)

This study conducts an information intervention using an online survey to measure the causal impact of personalized information on people's averting behavior, measured as the individuals' water filter uptake to protect themselves against PFAS pollution of drinking water at home. PFAS information changes from no information for the control group to generic information for treatment 1 and personalized information for treatment 2. Following this intervention, the survey introduces three PFAS-removing water filters already available in the market. It asks participants about their interest in purchasing a certified water filter on a scale of 1 to 10. After that, the survey requests them to upload proof of purchase if they bought a PFAS-removing water filter.

The experiment is conducted in two rounds, and participants are compensated after they complete each survey.

Intervention Start Date

2025-02-24

Intervention End Date

2025-03-23

Primary Outcomes

Primary Outcomes (end points)

Submitting proof of purchase.

Primary Outcomes (explanation)

Submission of proof of purchase: Participants can upload proof of purchase of their preferred PFAS-removing water filter.

Secondary Outcomes

Secondary Outcomes (end points)

Level of interest in purchasing a water filter and willingness to pay (WTP) for a water filter certified to remove PFAS.

Secondary Outcomes (explanation)

Level of interest in purchasing a water filter: Participants are asked to rate their interest in purchasing their preferred product among the options the survey introduced previously. The scale ranges from 1 (No interested at all) to 10 (Extremely interested).

WTP for a water filter certified to remove PFAS: The survey shows random integer values between $10 and $250 and asks participants whether they are willing to pay that amount to buy a water filter certified to remove PFAS.

Secondary measurements of interest: We track whether participants click on external links containing additional information on the water filter models we introduce in the survey.

Experimental Design

We construct demographic groups based on whether there is a pregnant woman, children at or under the age of 13, and individuals suffering from PFAS-related diseases in the household. Individuals in each demographic group will be randomly assigned to the control or treatment groups in equal proportions.

Experimental Design Details

Not available

Randomization Method

We set up the randomization using the survey flow in Qualtrics.

Randomization Unit

This study randomly allocates participants to the control and treatment groups within each of the eight demographic categories based on the presence of a pregnant woman, children aged 13 or under, and individuals in the household suffering from PFAS-related diseases.

Was the treatment clustered?

Yes

Experiment Characteristics

Sample size: planned number of clusters

Eight

Sample size: planned number of observations

Pretest: 300 participants. Nationally representative sample:1,500 participants. Additional samples: 350 participants.

Sample size (or number of clusters) by treatment arms

Since we lack prior information on the number of individuals living in households with children aged 13 or younger, pregnant women, or people with PFAS-related diseases, we cannot pre-estimate the distribution of participants across the control and treatment groups. However, the survey collects data on these characteristics to categorize participants into eight demographic groups. These groups will then be distributed equally and randomly among the control and treatment groups.

Minimum detectable effect size for main outcomes (accounting for sample design and clustering)

The study’s sample size is 2,000 subjects, determined by available funding. Based on a power calculation for a two-tailed test at a 0.05 significance level, with a power of 0.8 and an average proportion of 0.667 (using pretest data for the main outcome variable: whether a participant submitted proof of purchase), the minimum required sample size is 1,786 for an effect size of 1.85%. Additionally, the survey included questions about participants' intent to purchase. Based on data from the first round of the survey, the minimum required sample size for this variable is 965 subjects for an effect size of 7.7%.

Supporting Documents and Materials

IRB

Institutional Review Boards (IRBs)

IRB Name

The University of Rhode Island Division of Research and Economic Development, Office of Research Integrity

IRB Approval Date

2024-12-12

IRB Approval Number

IRB2223-277

Analysis Plan