Can Different Incentives Influence Participants’ Choice?

Monetary incentives are used to encourage people to perform a variety of different actions. Increasingly, they are used to encourage actions that are directly beneficial to individuals, such as engaging in healthy behaviors or quitting addictive drugs. Interestingly, however, there is little research comparing the effectiveness of different types of incentive schemes. The current project compares the effectiveness of incentive schemes that offer sure payments versus lotteries of equal expected value. Specifically, two studies examine whether people are more likely to participate in a task if they are offered: (1) a fixed sure payment, (2) a lottery of equal expected value, or (3) a choice between the sure payment and lottery. We hypothesize that lotteries will be the most effective incentive and that a choice between a lottery and a fixed payment will be least effective. We then examine which incentive people are more likely to select, when presented with a choice between a lottery and a fixed payment. We hypothesize that, even though lotteries provide greater motivation, people will tend to select fixed payments over lotteries if given a choice. Study 1 addressed these questions in the context of a campus blood drive, and provided tentative evidence that people prefer either type of incentive (lottery vs. sure payment) over the choice of incentives. Study 2 examined whether participants are more motivated to complete a survey in exchange for a sure cash payment, a lottery, or a choice between a sure cash payment and a lottery. Results from these studies could have important implications for researchers and volunteering organizations, which seek to provide incentives for participants at the lowest cost to the organization.