Reminding about good intentions: Field experimental evidence from an energy savings program during the energy crisis

Last registered on February 07, 2023


Trial Information

General Information

Reminding about good intentions: Field experimental evidence from an energy savings program during the energy crisis
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.



Primary Investigator

ZEW Mannheim

Other Primary Investigator(s)

PI Affiliation
ZEW Mannheim

Additional Trial Information

On going
Start date
End date
Secondary IDs
Prior work
This trial does not extend or rely on any prior RCTs.
Following the Russian war against Ukraine, Germany is suffering from a gas supply shortage. As a result, energy prices are skyrocketing and both the government and public utilities undertake efforts to encourage energy savings of households. We run a natural field experiment in cooperation with one of the largest energy suppliers in Germany to test a reminder intervention among households participating in an energy savings program. As part of that program, all households receive 5 cents for each kilowatt-hour natural gas they save during the winter 2022/2023 in comparison to previous years. However literature has shown, that many interventions lose effectiveness after a few months. We thus randomize mailings during that energy savings program which remind households of their initial energy savings plans.
External Link(s)

Registration Citation

Kesternich, Martin and Madeline Werthschulte. 2023. "Reminding about good intentions: Field experimental evidence from an energy savings program during the energy crisis." AEA RCT Registry. February 07.
Experimental Details


Intervention Start Date
Intervention End Date

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
Was the treatment clustered?

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)

Institutional Review Boards (IRBs)

IRB Name
IRB Approval Date
IRB Approval Number


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