Policy mixes more likely to succeed in fostering sustainable, climate-friendly behaviour

A meta-analysis testing interactions of environmental policies shows that combining behavioural and traditional instruments works better than deploying a single intervention.

A new study investigates the potential synergies between traditional and innovative climate policy interventions and finds that policy mixes tend to be more effective than individual approaches. In fact, policy mixes outperformed the most effective single intervention within the mix when implemented alone. Notably, combinations involving nudges and monetary incentives prove particularly effective in promoting pro-environmental behaviour.

The study, Synergies of interventions to promote pro-environmental behaviours – A meta-analysis of experimental studies, published today in the journal Global Environmental Change, finds that combining policies offers greater effectiveness in promoting pro-environmental actions than single policies.

In the realm of addressing climate change, an evidence-based approach to policymaking is imperative, particularly concerning strategies aimed at stimulating a pro-environment human behaviour.

With the 2030 climate targets of cutting GHG emissions by at least 55% as compared to 1990 levels, the EU has set a more ambitious path to achieve climate neutrality by 2050. As part of the European Green Deal, reaching these targets requires considerable changes in societal practices and in the behaviour of citizens.

The changes include, for example, minimising traffic-related emissions or reducing energy consumption. An effective combination of multiple instruments is therefore a conditio sine qua non to meet these ambitions.

Traditional economic instruments vs behavioural interventions

Traditional economic instruments have long been used to encourage citizens to adopt pro-environmental behaviours. These instruments include rewards, such as government incentives for home improvement, and taxes, like higher energy rates for consumption above a certain threshold. These approaches focus on providing external motivations for behaviour change. While they have shown some effectiveness, they may have limitations when implemented in isolation.

The advent of behavioural economics has revolutionised policymaking by introducing a new set of tools to encourage behaviours that are optimal for citizens and the environment. Nudges and boosts are two key concepts in this field that have gained traction in recent years. Nudges are subtle changes in the way choices are presented to citizens, guiding them towards positive behaviours without limiting their options or forcing a particular outcome.

For example, informing people about the positive behaviours of their peers can encourage them to follow suit. On the other hand, boosts are educational initiatives aimed at empowering individuals to make informed choices by enhancing their skills and decision-making abilities.

While traditional economic instruments and behavioural interventions have their merits, combining both approaches can be more effective than individual interventions. The effectiveness of policy mixes lies in their ability to complement each other and address the limitations of individual interventions.

For instance, implementing monetary rewards alone may lead to “motivational crowding out,” a phenomenon where external rewards diminish rather than increase motivation to engage in the behaviour targeted by the policy. Similarly, when nudges are implemented in isolation, they may be effective, but not as much as other traditional economic interventions. Hence, understanding whether these interventions complement each other becomes essential.

In this meta-analysis, a key method for synthesising evidence from numerous experimental studies, the authors screened more than 5000 scientific articles to identify relevant studies that met specific criteria, such as experimental design and relevance to the inquiry.

Ultimately, 37 studies were selected, and data on 57 different measures, termed “effect sizes”, were collected. These effect sizes helped compare the impact of different interventions, including taxes and subsidies, norm-nudges, boosts, and their combinations, on pro-environmental behaviour change.

This research underscores the importance of an evidence-based approach to policymaking, especially in the context of climate change and behaviour change interventions. By leveraging a wealth of experimental studies, this work provides evidence-based insights that can inform policymakers on the most effective strategies to foster sustainable behaviours.

This indicates that policymakers may use these mixes with low level of unintended consequences like motivational crowding out, as they offer a comprehensive and potentially more impactful solution to encourage positive behaviour change.

Source: European Commission | EU Science Hub (https://shorturl.at/cJQ07)