Salience of co-benefits from energy efficiency and the response to energy conservation nudges

Last registered on October 17, 2022


Trial Information

General Information

Salience of co-benefits from energy efficiency and the response to energy conservation nudges
Initial registration date
October 06, 2022

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
October 17, 2022, 3:56 PM EDT

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



Primary Investigator

Politecnico di Milano

Other Primary Investigator(s)

PI Affiliation
University of Milan
PI Affiliation
RFF-CMCC European Institute on Economics and the Environment (EIEE)
PI Affiliation
Politecnico di Milano

Additional Trial Information

On going
Start date
End date
Secondary IDs
Prior work
This trial does not extend or rely on any prior RCTs.
Green electricity contracts, where electricity is produced through renewable sources or where emissions are compensated, are becoming widespread. Utilities often offer this type of contract as a default for new customers. However, customers are not always fully aware of this characteristic. We aim to investigate whether disclosing or recalling customers the green component of their contract has a rebound effect on their electricity usage. Customers may react to such information by increasing consumption levels, as the moral cost of consuming a resource that produces little negative environmental externalities may drop. We also investigate a way to counteract a possible boomerang effect. In particular, we leverage the salience of the current energy crisis and the importance of energy transition. For the sample of customers with non-green contracts, we instead investigate how leveraging salient topics contribute to increasing energy conservation. We collaborate with an Italian utility which adopted a social information program for electricity. We randomly modify the contents of the Home Energy Report that customers regularly receive, adding a treatment that discloses the benefits of green energy and /or a treatment that emphasizes the importance of energy independence and the ecologic transition.
External Link(s)

Registration Citation

Bonan, Jacopo et al. 2022. "Salience of co-benefits from energy efficiency and the response to energy conservation nudges." AEA RCT Registry. October 17.
Experimental Details


We collaborate with a multi-utility mainly active in the North of Italy.
Since 2016, the company sends Home Energy Reports to its electricity and gas customers. The Report is similar to the one first proposed by Opower (Allcott, 2011) and includes the following features: static neighbor comparison, injunctive feedback on relative consumption, dynamic comparison with self, an awareness section called "Make the difference", saving tips. This study focuses on the electricity report. The report is sent to customers by email monthly or bimonthly soon after the electricity bill delivery, following the billing cycle.
The experiments consists in variations of the content of the report, aimed at making more salient the relationship between energy efficiency and relevant themes in current news. The treatments leverage these relationships to encourage energy conservation efforts and the shift to more sustainable consumption. In particular, we exploit the prominence in current news of two issues: energy independence and ecologic transition.
A more efficient use of electricity, the adoption of energy-saving technologies and the shift to green energy and renewable sources are tightly linked to the achievement of energy independence and of the ecologic transition. Importantly, energy conservation is important also for green customers, since renewable energy is scarce and its efficient use would allow it to meet the demand of a broader set of consumers. However, existing research on rebound effects after the adoption of energy-efficient technologies suggests that green customers may not feel the need to control their consumption level.

Given the composition of our sample, we therefore aim to address separate research questions for grey and green customers.

- For grey customers, we ask what the impact of making salient the importance of energy conservation and sustainable energy usage for energy independence and the ecologic transition is on customers' engagement with the utility, electricity consumption and investments in energy efficiency and renewable energy.
- For green customers, we address the previous research question on salience but we are also interested in: (i) whether reminding them -- or revealing to them -- the implications of their contract on the environment, particularly that their electricity consumption generates no Co2 emissions (or that their CO2 emissions are compensated), causes a rebound effect in terms of electricity consumption, investment in energy efficiency and engagement; and (ii) whether making salient the importance of continued effort to save energy in order to help the ecologic transition and energy independence can offset any rebound effect.

This implies that we randomise grey customers into a \textit{salience} and control treatment, where the salience treatment reminds them of the impact of their consumption on the ecologic transition and energy independence. Green customers instead are allocated to one of four conditions, resulting from the interaction of two treatment dimensions, in a factorial design. The first treatment dimension (T1) mirrors the one for grey customers, comparing a control and a salience condition. The second treatment dimension (T2) tests the effect of disclosing the benefits of green energy -- the \textit{green disclosure} condition -- to a control condition. This 2x2 design for green customers results in 4 groups: control, T1 only, T2 only, both T1 and T2.

We implement the treatments by modifying the "Make a difference" and tip sections of the report.
Intervention Start Date
Intervention End Date

Primary Outcomes

Primary Outcomes (end points)
- Engagement, measured as clicks on the links embedded in the tips.
- Electricity consumption
Primary Outcomes (explanation)

Secondary Outcomes

Secondary Outcomes (end points)
Investments in energy efficiency and renewable energy
Secondary Outcomes (explanation)

Experimental Design

Experimental Design
Separately for green and grey customers, we apply a stratified individual level randomization, to maximize ex-ante balance across treatment and control group along a battery of important observable characteristics.
Within each of the 28 strata, we sort customer by pre-treatment electricity usage and assign adjacent customers to treatment and control group. In particular, for grey customers we assign every other customer to the control group (about 50% treatment and 50% control). For green customers, every customer is assigned, in turn, to one of the following conditions: treated salience-treated green disclosure; treated salience- control green disclosure; control salience-treated green disclosure; control salience-control green disclosure. Each group includes about 25% of the sample.
Experimental Design Details
Randomization Method
Randomization done in office by a computer
Randomization Unit
Was the treatment clustered?

Experiment Characteristics

Sample size: planned number of clusters
No clusters
Sample size: planned number of observations
156,065 customers
Sample size (or number of clusters) by treatment arms
Grey customers: salience treatment (N=52,996); salience control (N=53,055)
Green customers: treated salience-treated green disclosure (N=24,981); treated salience- control green disclosure (N=24,961); control salience-treated green disclosure (25,033); control salience-control green disclosure (24,993.
Minimum detectable effect size for main outcomes (accounting for sample design and clustering)
see PAP

Institutional Review Boards (IRBs)

IRB Name
IRB Approval Date
IRB Approval Number
Analysis Plan

Analysis Plan Documents


MD5: 935e9a2aefeb8cf92cd8341a52b6f2ff

SHA1: 9254e0434f8b5b0d07f5c65d220be8ac8d02c6b1

Uploaded At: October 06, 2022


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