Spillovers from Behavioral Interventions: Experimental Evidence from Water and Energy Use

Last registered on April 23, 2018


Trial Information

General Information

Spillovers from Behavioral Interventions: Experimental Evidence from Water and Energy Use
Initial registration date
April 20, 2018

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
April 23, 2018, 6:25 PM EDT

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


Primary Investigator

Iowa State University

Other Primary Investigator(s)

PI Affiliation
University of California, Davis
PI Affiliation
University of California, Davis
PI Affiliation
University of California, Davis

Additional Trial Information

Start date
End date
Secondary IDs
This paper provides experimental evidence that behavioral interventions spill over to untreated sectors by altering consumer choice. We use a randomized controlled trial and high-frequency data to test the effect of social norms messaging about residential water use on electricity consumption. Messaging induces a 1.3% to 2.2% reduction in summertime electricity use, a nding replicated in a separate experiment. Empirical tests and household survey data support the hypothesis that this nudge alters electricity choices. An engineering simulation suggests that complementarities between appliances that use water and electricity can explain only 26% of the electricity reduction. Incorporating the cross-sectoral spillover increases the net-bene ts of the intervention by 62%.
External Link(s)

Registration Citation

, et al. 2018. "Spillovers from Behavioral Interventions: Experimental Evidence from Water and Energy Use." AEA RCT Registry. April 23. https://doi.org/10.1257/rct.2921
Former Citation
, et al. 2018. "Spillovers from Behavioral Interventions: Experimental Evidence from Water and Energy Use." AEA RCT Registry. April 23. https://www.socialscienceregistry.org/trials/2921/history/28667
Experimental Details


We partnered with a municipally owned water and electric utility and the water technology vendor WaterSmart to evaluate the potential energy and water savings of non-pecuniary water conservation instruments.
Intervention Start Date
Intervention End Date

Primary Outcomes

Primary Outcomes (end points)
The purpose of the intervention was to evaluate the impact of a non-pecuniary water conservation instrument on hourly household electricity, natural gas, and water use.
Primary Outcomes (explanation)

Secondary Outcomes

Secondary Outcomes (end points)
Secondary Outcomes (explanation)

Experimental Design

Experimental Design
The sample consists of 7,341 single-family homes served by our partner utility, Burbank Water and Power. To be eligible for participation in our study, a household needed to reside in a single-family home and have six months of meter readings before the launch of the experiment. Of the roughly 18,000 eligible homes, we randomly assigned 4,559 accounts to the WaterSmart treatment and 2,78 2to control, where the relative size of the treatment group and control group was determined by the project sponsors.

We sent bi-monthly Home Water Reports (HWRs) to all treatment households over the treatment year. The HWR includes a social comparison, water savings recommendations, and information about the report and BWP's conservation programs. The social
comparison provides a household with information on its current water use and compares its use to that of similar households and an `ecient' household.4 An injunctive norm accompanies the comparison, conveying pro-social behavior through the display of a smiling or
frowning face depending on the household's water use relative to its neighbors. The report also includes individualized recommendations on ways to use water more efficiently.
Experimental Design Details
Randomization Method
We implemented the randomization in partnership with WaterSmart. We utilized the "big stick" method of rerandomization to randomly assign eligible accounts to treatment or control and conducted the randomization in private using a random number generator.
Our randomization protocol formally tested for and ensured covariate balance in the mean and variance of pre-treatment monthly water use across control and treatment accounts. Rerandomization of households into treatment and control continued until the p-value from a test of the joint signi cance of these covariates in explaining assignment to treatment exceeded a 0.25 threshold.
Randomization Unit
Randomization units were single-family households.
Was the treatment clustered?

Experiment Characteristics

Sample size: planned number of clusters
Our sample consists of 7,341 single-family homes.
Sample size: planned number of observations
We use hourly water and electricity use data for all 7,341 households in the utility area over the treatment year to evaluate the experiment.
Sample size (or number of clusters) by treatment arms
4,559 accounts were randomly assigned to treatment and 2,782 to control.
Minimum detectable effect size for main outcomes (accounting for sample design and clustering)

Institutional Review Boards (IRBs)

IRB Name
Study has received IRB approval. Details not available.
IRB Approval Date
Details not available
IRB Approval Number
Details not available


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