“We show that people are less likely to engage in environmental behavior if they are paid by the hour, a form of compensation that leads people to see their time as money,” Whillans and Dunn write in the journal Organizational Behavior and Human Decision Processes.
In their first study, Whillans and Dunn analyzed data from a nationally representative sample of over 10,000 individuals from 5000 British households. The researchers compared the pro-environmental behavior of 2,802 hourly paid respondents and 4,128 salaried respondents.
As predicted, hourly workers reported less frequent engagement in environmental behaviors compared to salaried workers, even after a number of demographic factors were taken into account.
In another study, 52 students were asked to complete identical calculations of future income in a year. Half the students were explicitly asked to think about their time as money through an hourly wage, while the control group simply completed the exercise.
The students were then asked to cut a series of shapes out construction paper. The experimenter mentioned that participants could discard their scrap paper in a trash bin inside the room or a recycling bin just a few feet outside the room.
Students prompted to think of an hourly wage were far less likely to reach for the recycling even though it only took an extra 3 seconds to recycle the scrap paper.
However, Whillans and Dunn found that the detrimental effect of seeing time as money could be eliminated when people saw environmental behavior as something they could benefit from themselves.
A total of 179 participants completed a task in which they were asked to imagine themselves as a consultant for a fictitious company. Half of the participants were assigned to a billing condition in which they charged $0.25 for each minute of their time. Those in the control condition simply completed the task.
Participants then took a true-false quiz in which environmental behaviors were framed as either self-beneficial (e.g., staff who carpool get a premium parking spot) or generally altruistic (e.g., driving a car is good for the environment).
Finally, the volunteers completed the paper cutting task with the option to either recycle or throw away their scraps.
When pro-environmental behavior was framed as a generally altruistic act, 45% of those in the billing task recycled their scrap paper, compared to 73% of participants who completed the control task. However, when environmentally friendly behavior was framed in self-beneficial terms, there was no significant difference in recycling rates between the billing group and the control group.
Although the researchers acknowledge that most of the effects they found were relatively small, they emphasize that even minor shifts in behavior can lead to meaningful consequences. For example, if each of the 75 million hourly workers in the US recycled an additional pound of paper each year, 28 million trees would be saved.
“Reminding people how much money their time is worth can have far-reaching effects on the decisions they make about their time, pointing to a novel explanation for the limited impact of environmental campaigns on everyday behavior,” the researchers conclude.