Do energy-saving nudges deliver during high-price periods? Field experimental evidence from the European Energy Crisis

Last registered on October 28, 2025
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Pre-Trial

Trial Information

General Information

Title
Do energy-saving nudges deliver during high-price periods? Field experimental evidence from the European Energy Crisis
RCT ID
AEARCTR-0010890
Initial registration date
January 30, 2023

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 07, 2023, 11:13 AM EST

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

Last updated
October 28, 2025, 12:56 PM EDT

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

Locations

Country
Germany
Region

Primary Investigator

Name
Madeline Werthschulte
Affiliation
ZEW Mannheim
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Other Primary Investigator(s)

PI Name
Martin Kesternich
PI Affiliation
Paderborn University
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PI Name
Vicky Leoni Tinnefeld
PI Affiliation
Paderborn University
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Additional Trial Information

Status
Completed
Start date
2022-10-01
End date
2023-04-01
Keywords
Behavior, Environment & Energy
Additional Keywords
JEL code(s)
Secondary IDs
Prior work
This trial does not extend or rely on any prior RCTs.
Abstract
Urged by the European Energy Crisis and the threatening consequences of severe natural gas shortages, energy providers launched gas-saving initiatives incorporating financial incentives to reduce residential natural gas consumption. In collaboration with one of Germany’s largest energy providers, we conducted a natural field experiment (N = 2,598) to evaluate the effectiveness of a behaviorally-guided co-design of such a gas-saving initiative by implementing two established behavioral instruments -- reminders of gas saving intentions and descriptive norm feedback. Our findings show limited effectiveness of the behavioral instruments during the high-price period. The feedback risks a ``boomerang effect” among households with above-average initial savings, who reduce their conservation efforts in response. The reminder does not significantly enhance savings in our main specifications, yet, realizes 1 percentage point savings in alternate models refining for outliers. Potential mechanisms include a significant intention-action gap and misperceived effectiveness of energy-saving actions, which are not alleviated by the reminder.
External Link(s)

Registration Citation

Citation
Kesternich, Martin, Vicky Leoni Tinnefeld and Madeline Werthschulte. 2025. "Do energy-saving nudges deliver during high-price periods? Field experimental evidence from the European Energy Crisis." AEA RCT Registry. October 28. https://doi.org/10.1257/rct.10890-2.1
Sponsors & Partners
Experimental Details

Interventions

Intervention(s)
Intervention (Hidden)
Intervention Start Date
2022-10-01
Intervention End Date
2023-03-31

Primary Outcomes

Primary Outcomes (end points)
Natural gas consumption (in kWh)
Change in natural gas consumption compared to previous years
Primary Outcomes (explanation)

Secondary Outcomes

Secondary Outcomes (end points)
Interest in additional energy saving webinars (yes/no)
Executed energy saving actions (yes/no)
Secondary Outcomes (explanation)

Experimental Design

Experimental Design
With the need of drastic energy consumption reductions in winter 2022/2023, our cooperation partner launched an energy savings program. The program started in October 2022, and all participating households will receive 5 cents for every kilowatt-hour of natural gas saved until April 2023 compared to previous years’ natural gas consumption. In addition, bonuses of 20 (40) euros are promised if all participating households achieve savings of 10% (15%).

By October 2022, about 2500 households signed up for this program. During the program, participants receive two mailings (1) in mid-December to inform them about their current savings and the savings of all participating households, (2) in mid-February to inform them about gas storage levels in Germany.

Our natural field experiment randomizes the information content provided in these two mailings. While a control group receives the standard mailings described above, a treatment group receives additional information. This additional information is designed to remind participants about (i) their initial energy saving plans, (ii) the financial incentive of saving energy, and (iii) their planned energy saving actions to achieve these savings.

We thereby connect the plan-making and reminder literature. While making precise plans has proven to be effective to follow through with good intentions, these type of nudges often lose effectiveness after a few months. This might be particularly true in the German energy context, as household typically do not have feedback systems that inform them about consumption and achieved savings. Our intervention thus aims to remind households of the plans they made at the time they signed up for the energy savings program.

We will estimate the impact of this intervention on individual natural gas consumption in the period from October 2022-April 2023, and the change in natural gas consumption compared to the previous years. Further secondary outcomes will be (1) interest in energy saving webinars and (2) stated energy saving actions undertaken. We measure the interest in energy saving webinars through clicks in the mailings on links redirecting to the sign-up for such webinars. We will run a survey in April 2023 to ask participants for the energy saving actions they undertook during the winter to save energy.
Experimental Design Details
Randomization Method
Randomization by computer
Randomization Unit
Individual
Was the treatment clustered?
No

Experiment Characteristics

Sample size: planned number of clusters
2535 (number of individuals participating in the energy savings program)
Sample size: planned number of observations
2535 (number of individuals participating in the energy savings program)
Sample size (or number of clusters) by treatment arms
1267 (50:50 for control- and reminder-mailing)
Minimum detectable effect size for main outcomes (accounting for sample design and clustering)
Supporting Documents and Materials
IRB

Institutional Review Boards (IRBs)

IRB Name
IRB Approval Date
IRB Approval Number
Analysis Plan

Post-Trial

Post Trial Information

Study Withdrawal

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Intervention

Is the intervention completed?
Yes
Intervention Completion Date
March 31, 2023, 12:00 +00:00
Data Collection Complete
Yes
Data Collection Completion Date
April 01, 2023, 12:00 +00:00
Final Sample Size: Number of Clusters (Unit of Randomization)
Was attrition correlated with treatment status?
No
Final Sample Size: Total Number of Observations
N = 2,382
Final Sample Size (or Number of Clusters) by Treatment Arms
Control group N = 1,199, treatment group N = 1,183.
Data Publication

Data Publication

Is public data available?
No

Program Files

Program Files
Reports, Papers & Other Materials

Relevant Paper(s)

Reports & Other Materials