Given the multitude of environmental issues we currently face (e.g., climate change, drought, environmental injustices), social and environmental scientists are constantly seeking effective ways to influence any human behavior linked to these problems. One of the oldest tricks in the behavioral scientist’s book is financially incentivizing sustainable behavior. For example, some states such as Michigan pay people to recycle their cans and bottles. Other places, like Fairfax County, Virginia, instead charge fees to households that produce too much waste. And some educational entities, such as the University of Southern California, inspire their students to save energy by holding competitions across dormitories, rewarding students in the winning dorm with a prize. (The event is called “Do It In The Dark”; the prize is apparently free massages for winning students; interesting reward, given the event name).
So, does paying people to engage in environmental behaviors actually influence their actions? Humans are rational creatures, or at least somewhat rational, and increasing the financial benefits of engaging in environmental behaviors may improve the cost-benefit ratio enough to get more people to change their choices. In the health behavior area, we have evidence that incentives are generally an effective route to changing behaviors, although the evidence is mixed concerning their ability to influence behavior after the incentive has been removed. So, given these findings, why wouldn’t incentives be an effective approach to changing environmental behaviors?
Well, I think a lot of people who care about the environment are turned off by the idea that we should pay people to engage in environmental actions. Shouldn’t people just inherently care about saving energy? Why do we need to pay people? People should just do the right thing. Social and environmental scientists themselves have similar concerns about paying people to engage in positive environmental behaviors. Some worry that incentives could actually decrease people’s “intrinsic” or personal motivation to engage in environmental actions. The idea is that paying people to do things they are already doing, or that they already care about, can essentially trick them into thinking that they are now only engaging in the behavior for financial reasons. And, once you remove the financial incentive, they either go back to what they were doing before the incentive, or, even worse, they actually perform the original behavior less frequently. So, if we pay people to save energy at home – let’s say by giving them credits toward their next energy bill – and they are already making an effort to save energy at home, then paying them will only lead to further reductions in energy use while the payment scheme remains in place. Potentially upon removal of the incentive they’ll just go back to using the original amount of energy, or they’ll even forget that they used to care about saving energy in the first place and will use even more energy than before.
Last blog I discussed using meta-analysis to provide clarity when there are numerous studies on a given topic, sometimes with those studies even contradicting one another. My colleagues and I used the same kind of approach – a quantitative meta-analysis – to examine the evidence for using incentives to influence environmental behaviors (published version here, accepted version here). There have been a couple of meta-analyses on this topic before (here and here), but they both only considered incentives as a singular approach. So, we used a theoretical paradigm, developed by a couple of my colleagues (Rachel Burns and Alex Rothman, among others) that considers how different types of incentives may be more or less effective. For example, we know from classic research by B. F. Skinner and others that it can sometimes be more effective to use what’s called a “variable-ratio reinforcement schedule," where people are not constantly provided the incentive each time they perform the behavior. A great example of this approach is slot machines, which are so addictive in part because you never know when the payoff is going to come. There’s some reason to believe that using these kinds of reinforcement schedules could be effective when changing environmental behaviors.
We also found that while the incentives were in place, variable-ratio schedules of reinforcement tended to be more effective than fixed schedules of reinforcement (i.e., always giving a person the financial reward each time they engaged in the behavior). We hoped to test whether incentives construed as rewards (e.g., being paid to recycle) versus punishments (e.g., paying a fee for producing too much household waste) were more effective, but unfortunately we only had one study that used a punishment approach, so we really couldn’t examine that issue.
Now, as I mentioned before, social and environmental scientists sometimes have concerns (here and here, for example) that using financial incentives to influence environmental behaviors could “crowd out” people’s intrinsic motivations for engaging in environmental behaviors. We didn’t examine the influence of financial incentives on intrinsic environmental motivation in our meta-analysis because there aren’t enough studies on the topic yet to warrant a meta-analysis. Very recent experimental work has begun to test whether people’s intrinsic environmental motivations are actually influenced by incentives, but this work is still quite young. Some early evidence suggests it can decrease intrinsic motivation, while other results suggest incentives can lead to maintained behavior even if intrinsic motivations decrease.
Ultimately, I’m most concerned about behavior initiation and maintenance. What helps people change their environmental behaviors, and what helps them maintain those behaviors over time? There are real reasons to be concerned about how incentives affect intrinsic motivations, although I think the literature is still too young in the environmental area to be conclusive. I also think there are real limitations to our meta-analysis; more studies with more participants would further increase confidence in the findings. And, research in the area needs to more consistently use relevant social-scientific theory to design, implement, and analyze results from incentive interventions. The studies included in our meta-analysis were rarely guided by explicit theory. This is important, as using theory would make it more likely that we design studies that consider how incentives affect a range of relevant beliefs, including intrinsic motivation to help the environment. And better use of theory would also help us consider how incentives could lead to maintained behavior, which we did find evidence for in our meta-analysis.
Could incentives help people form habits? Could they help people appreciate that there are inherent benefits to engaging in many environmental behaviors, such as both the financial and environmental benefits of saving energy at home? Do people develop a sense of confidence or competency over time when paid to change their behavior, such as free bus tickets leading people to learn how and when to take the bus, with these beliefs perhaps being maintained even after the tickets are removed? These questions, and others, are worthy of future exploration.
What do you think?