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.