Subtle behavioural cues to spark long-term eco-friendly practices

Financial incentives, like grants for energy-saving home improvements, are important to cover upfront costs and encourage people to go green. But they might also have unwanted effects on behaviour over time, as individuals may feel they have done their part and hence lose interest in continuing to act in eco-friendly manner, using more energy elsewhere or flying more often. 

This is an important challenge in light of a looming global climate crisis. Immediate actions can help, like reducing home energy use or driving less, but what really matters is ensuring that these actions become long-term habits, a lifestyle. Governments often need to use monetary incentives, such as subsidies or rebates, to encourage environmentally-friendly but costly actions. While these financial tools are effective in promoting the targeted action, they may have unintended consequences on behaviour change over time.

How can policymakers prevent these negative effects and encourage long-term green habits? According to a new study published in the Journal of Environmental Economics and Management, behavioural nudges, such as messages that reconnect ourselves to our personal or social norms, can help prevent these unwanted effects, known as negative behavioural spillovers.

The experimental online study involved nearly 4 000 people to test if mixing behavioural nudges with financial incentives would lead to more lasting eco-friendly actions compared to using monetary instruments alone.

What sets the study apart from other similar research is that it offers the first large-scale proof that mixed approaches work in reducing the negative effects of financial rewards alone and inspire long-term, meaningful green habits that can make a real difference in fighting climate change.

The behavioural nudges tested in the study included simple reminders of social norms (e.g. “Do you think a long-haul flight is acceptable for your peers”?), or of personal values before making a decision (e.g. “Is taking a long-haul flight in line with your moral standards?”). The nudges appeared to prevent backsliding to less sustainable behaviours.

By providing empirical evidence that adding behavioural nudges to financial incentives can lead to more persistent sustainable actions, the study opens up new possibilities for designing effective environmental policies aiming to inspire long-term, impactful behaviour changes.

This approach directly supports key EU goals like affordable housing and reducing carbon emissions. By ensuring that financial incentives paired with norm-nudges drive both immediate and long-term sustainable behaviour, this work backs the EU's aims of promoting energy-efficient home improvements and supporting the broader carbon reduction agenda.

Background

This study is the final output of the JRC Exploratory Research project PoliSpill (Policy mix and behavioural spillovers). The project aims to understand the impact of behavioural mechanisms on pro-environmental behaviours and how different policies and combinations of policies can influence them. By examining the effectiveness of policies based on their implementation, the results of this study can offer evidence-based insights into the most effective strategies that policymakers can employ to promote sustainable behaviours.

Related links

The more the better? Synergies of prosocial interventions and effects on behavioural spillovers

Synergies of interventions to promote pro-environmental behaviors – A meta-analysis of experimental studies

Combining interventions to promote pro-environmental behaviours - The role of incentives and norms for effective climate interventions

Environmental policy mixes have a high potential, but must be handled with care