Cross-effects of behavioural strategies on household resource use

Key messages:

• A simple low-cost water conservation report reduced household water consumption by 2.4% over two years
• The water nudge also cut electricity use by 1.7%, showing that small behavioral interventions can influence multiple resources.
• When paired with additional nudges, water use was cut by 1.4% and electricity use by 0.5% over two years
• Households receiving the water report were less likely to cancel utility contracts (-2.8% gas cancellations, -3% electricity cancellations), showing added value for firms.
• Effects lasted across a two-year period, demonstrating durability of behavior change.

A small nudge can have a big impact. A study published in Journal of Environmental Economics and Management and led by CMCC researcher Jacopo Bonan demonstrates that a “nudge” – a behavioral intervention based on personalized information – can encourage households to cut not only their water use, but also their electricity consumption.

The research was based on a two-year randomized controlled trial in collaboration with a multi-resource company in Italy. Households received personalized reports comparing their water consumption with that of their neighbors, along with tips for conservation. The results are interesting: households receiving the report reduced their water consumption by 1.4% and electricity consumption by 0.5%. Even more notably, for those who received only the water report (without additional nudges), reductions reached 2.4% for water and 1.7% for electricity.

Beyond encouraging more sustainable behaviors, the intervention also improved customer retention: gas contract cancellations decreased by 2.8% and electricity cancellations by 3%.

However, the study also reveals a significant trade-off: when households received multiple nudges at once (for water, electricity, and gas), the overall effectiveness of each intervention declined. According to the authors, an overload of behavioral messages can saturate people’s limited attention and reduce their capacity to act.

“In recent years, the use of behavioral interventions to promote pro-environmental actions has grown significantly and our research contributes to this growing body of work,” says Bonan. “However, while behavioral interventions are attractive for their cost-effectiveness, they alone cannot drive the sweeping systemic changes needed to meet climate goals. More ambitious policies that reshape incentives are essential.”

This research provides valuable insights into the design of effective, behaviorally informed interventions that can help households save money, reduce their environmental footprint, and strengthen firms’ engagement strategies.