Financial rewards for long-term environmental protection

Monetary rewards are effective for promoting environmental protection. But can protecting the environment for financial reasons result in durable increases in people's inherent motivation to protect the environment—that is, their environmental attitude? With this research, we aimed to experimentally test the long-term efficacy of financial incentive/reward interventions. We randomly assigned a sample of 336 (mostly) students to either of two conditions. Participants in the treatment condition were offered a financial reward for choosing vegetarian lunches. As expected, we found that the monetary reward increased the proportion of vegetarian lunches regardless of students' preexisting environmental attitude levels. The following week, after the financial reward was discontinued, environmental attitude continued to account for the proportion of vegetarian meals, whereas the previous receipt of a financial reward no longer had an effect. Thus, the long-term efficacy of monetary rewards, at least under the conditions of this research, seems questionable.