Even though there is some disagreement as to who is responsible for climate change, it is beyond substantial scientific doubt that climate change is a major threat for humanity in the 21st century. However, there still is doubt among the public. Why? There is an intuitively appealing theory why this is the case: Solution aversion. The theory attempts to explain why Republicans are much more likely to deny the reality of man-made climate change, while Democrats tend to accept it as fact. The model proposes that people deny the existence of a problem partly or primarily because they disagree with the solutions that have been proposed to solve the problem. In the case of climate change these proposed solutions would be regulations that disagree with what conservatives favor: market solutions.
Then behavioral economics enters the field, or how some researchers call it: “Regulation for Conservatives”. This field comes up with solutions to challenges posed by human behavior causing climate change. These interventions, often called nudges, appeal not just to people in favor of state intervention, but also to more liberal people. They take into account that people behave boundedly rational, change behavior at low cost, do not coerce, and do not make behavior economically more costly (have a look at this figure by Christina Gravert to help decide whether something really is a nudge). Additionally, nudges not only appeal to Republicans, they also avoid drawbacks inherent in economic incentives that aim to motivate pro-social behavior. Economic incentives can reduce intrinsic motivation to protect the climate. When people that protect the climate because they inherently think it is important suddenly receive external (e.g. monetary) compensation for this, they potentially reduce their intrinsic motivation. It gets crowded out. Where, after all, is the fun, the satisfaction, the warm-glow feeling in doing something good, if you get paid for it? Especially if others know you get paid for it? Why should they believe you are doing it because you want to, and not because you get paid to?
Nudges seem to circumvent this dilemma. In addition, research of my colleagues and me suggests that students that are being nudged by a default value to contribute a significant amount of money to climate protection do not react differently to the default even if they easily feel threatened in their behavioral autonomy by external interventions. This may sound similar to motivation crowding, but it is not. It is something you may or may not have heard about, but which you definitely have felt or thought about once in your life: Psychological reactance.
When a person senses that her individual freedom of behavior is threatened, e.g. due to a nudge, she may experience a state of psychological reactance. This experience motivates her to re-attain the restrained freedom. How? Most likely, the person attempts to do exactly the opposite of what the cause of threat tried to get her to do. Our findings suggest that this specific default value does not appear as a threat to behavioral freedom to people that very easily feel threatened.
So that’s great: Neither reactance nor motivation crowding pose a challenge for nudges. But can nudges substitute economic incentives to mitigate climate change? Can nudges change individual behavior enough so that voluntary (?) individual contributions to climate protection, even without pecuniary or legislative interventions, can stop climate change? Normally, one begins the article with some basic facts and then proposes ideas, backed-up by research, but I am providing you the facts now:
In 2014, global CO2 emissions amounted to 34,081.71 million tonnes (see this site for great visualizations and downloadable data sets, based on which I calculated this number). Of course, per capita emissions are huge in the most developed countries. In the US, it was on average 16.26 tonnes in 2014.
Reaching the 2 °C target set in the Paris 2015 agreement, ”may require changes in lifestyle choices from the high-carbon individuals estimated to produce nearly 50% of emissions”. These changes require a shift to an average annual emission of 2.1 tonnes per person per year by 2050. What are the most promising actions? I asked this question to a lot of friends and neither of them came up with answer a recent publication found, even though its carbon reduction potential by far outweighs the potential of the other high-impact activities: Don’t get a child. This is followed by: not owning a car, avoiding transatlantic flights, buying green energy, buying a more efficient car, switching to an electric (or no) car, and a plant-based diet. Unfortunately, the authors estimate that eating meat, taking one roundtrip, transatlantic flight per year would already exceed your limit of 2.1 tonnes.
Can nudges motivate people to do these things better than economic incentives can? Think about it this way: What would you rather like? Being forbidden to get a child, receiving financial compensation for not getting a child, or being nudged towards not getting a child, even though the choice is ultimately yours? Or think of it differently: would you rather have forced Donald Trump to not withdraw from the Paris 2015 agreement, or would you rather have nudged him?