Isolating the effect of injunctive norms on conservation behavior: New evidence from a field experiment in California

Abstract

Social norms messaging campaigns are increasingly used to influence human behavior, with social science research generally finding that they have modest but meaningful effects. One aspect of these campaigns in practice has been the inclusion of injunctive norms messaging, designed to convey a social judgment about one's behavior (often in the form of encouraging or discouraging language, or a visual smiley or frowny face). While some prominent research has provided support for the use of such messaging as a tool for positive behavior change, causal evidence on the effect of injunctive norms messaging as a motivator (as opposed to just one part of a multifaceted messaging campaign) is limited. This paper presents a field experiment on water conservation behavior conducted by an organization in California, involving over 40,000 households, which provides some of the most precise evidence to date regarding the effect of injunctive norms on decision making. I find that not only do injunctive norms encourage conservation behavior, there is also no evidence that they discourage individuals from further attending to norms messaging-regardless of whether the social judgment conveyed is negative or positive. Taken together, this suggests that injunctive norms are a useful tool in "nudge"-style campaigns tackling behavior change.

A Social Norm Nudge to Save More: A Field Experiment at a Retail Bank

“…For instance, we find very similar effects for subsamples of households who arguably have more opportunities to save and for those who live in more homogeneous neighborhoods. 9 Also, we find no difference in estimated treatment effects when we drop those clients from the sample who, at the moment of receipt of the email, have either a surprisingly high or low buffer. 10 Lastly, results are the same if we focus on a group…”

“…By virtue of our design, we can examine the existence of spillover effects. In the design stage, we followed the approach in 9 See Bicchieri and Dimant (2019) for a discussion of the importance of using a not-too-dissimilar reference group in social norm nudges.…”

The interaction of descriptive and injunctive social norms in promoting energy conservation

“…Our findings have implications for the design of social information programmes that rely on the combination of different types of norms to maximize behavioural change. Similar programmes are used in several domains, such as tax compliance 26,27 , charitable giving 28 or water conservation 29 . According to our conceptual framework and empirical results, no single type of normative information is more effective in absolute terms.…”

Nudging with Care: The Risks and Benefits of Social Information

“…When the environment pointed to a negative descriptive norm (littering) but subjects were exposed to a positive normative message, the latter had a greater effect on behavior. In the already mentioned experiment by Schultz et al (2007), signaling normative information in addition to the empirical information (by adding a smiling emoticon next to a homeowner's electricity usage if it was below average or a frowning one if it was above average), those who consumed above average continued to reduce their consumption, while those who consumed below average maintained their originally low energy usage (see also Bhanot, 2018).…”