We compare the effect of two experimental interventions designed to increase physical exercise: a direct economic payment in the form of a certain/fixed financial incentive and a behavioral economic incentive in the form of a lottery based financial incentive.
External Link(s)
Citation
Katare, Bhagyashree. 2018. "Impact of Lottery vs Fixed Incentive on Health Behavior." AEA RCT Registry. November 17. https://doi.org/10.1257/rct.3558-1.0.
Visits to the recreation center, as a proxy for Physical exercise
Primary Outcomes (explanation)
The data is automatically generated from the student card swipes for gaining access to the recreation center.
Secondary Outcomes (end points)
Secondary Outcomes (explanation)
Experimental Design
The intervention spanned for 8 weeks from January to March 2018. 1486 freshmen were recruited during their student orientation to participate in the research project. They were randomly assigned to the three treatment groups and a control group. The three treatment groups were 1) fixed incentive group that received a fixed amount for each visit to the recreation center in a week, 2) high lottery incentive group, the participants were entered in a high payout low probability lottery for every visit to the recreation center in a week, and 3) low lottery incentive group, the participants were entered in a low payout high probability lottery for every visit to the recreation center. All the three treatment group payouts had the same expected value. Participants in the treatment groups received an email every Monday morning over the eight-week period reminding them about their chance of winning the lottery or the fixed payment. The probability of winning the lottery remained same over the period of the intervention. Treatment group students received their payout at the end of every week in the form of an online gift card.
Experimental Design Details
The interventions were conducted in spring 2018 at a large public university in the Midwest, US. The intervention spanned for 8 weeks from January to March 2018. 1486 freshmen were recruited during their student orientation to participate in the research project. They were randomly assigned to the three treatment groups and a control group. The three treatment groups were 1) fixed incentive group that received a fixed amount for each visit to the recreation center in a week, 2) high lottery incentive group, the participants were entered in a high payout low probability lottery for every visit to the recreation center in a week, and 3) low lottery incentive group, the participants were entered in a low payout high probability lottery for every visit to the recreation center. All the three treatment group payouts had the same expected value. Participants in the treatment groups received an email every Monday morning over the eight-week period reminding them about their chance of winning the lottery or the fixed payment. The probability of winning the lottery remained same over the period of the intervention. Treatment group students received their payout at the end of every week in the form of an online gift card.
Randomization Method
randomization done in office by a computer
Randomization Unit
Individual level randomization
Was the treatment clustered?
No
Sample size: planned number of clusters
No clusters.
Sample size: planned number of observations
1486 individuals recruited for the experiment. Final sample size =1210
Sample size (or number of clusters) by treatment arms
292 Control, 291 in Treatment group 1, 293 in Treatment group 2 and 290 in Treatment group 3
Minimum detectable effect size for main outcomes (accounting for sample design and clustering)