We will draw a sample of all benefit-eligible employees at the university (approximately 12,000). An invitation will be sent to each employee, asking them to participate in a baseline survey. Employees will receive a gift card of $30 for completing the survey. Respondents to the baseline survey will comprise our core sample.
The core sample will be divided randomly into either a control group, or one of 4 treatment groups, Treatments A - D. Treatment groups A, B and C will receive a cash incentive of $0, $100, and $200, respectively, for completing the biometric screening + HRA. Within each group, half of the members will also be offered $25 for each of up to two, semester-long wellness activities that are completed during the year. The other half will be offered $75 for completing up to two, semester-long wellness activities during the school year.
The final treatment group, D, will feature a clustered design. The baseline survey will elicit information about workplace social networks. We will use standard methods to map those networks among those employees that do respond to the baseline survey. Provided that we are able identify a sufficient number of non-overlapping, local neighborhoods, we will systematically assign a share of neighborhood members to either the control group or the treatments of groups A, B and C with equal probability. Treatment group D will feature a higher share of control group members in a given social network than members of treatment groups A, B and C.
Upon completion of the baseline survey and treatment group assignment, employees will be invited to schedule a biometric screening. Once the biometric screening is completed, an online HRA will be made available for participants. Following completion of the HRA, participants will be allowed to enroll in up to two wellness activities.
One year later, members of the control and treatment groups will be invited to complete an additional follow-up survey and biometric survey. Incentives will be increased in the follow-up period in order to minimize attrition. Participants will be offered either $25 or $35 dollars for completing the follow-up survey, and either $150 or $250 for completing a follow-up biometric screening. In order to minimize attrition, these incentives may be modified based on information gained from the first year of the experiment.
Our ability to implement the peer-effects design, i.e. treatment group D, depends on the structure of social networks in our data. We cannot observe these prior to collecting baseline survey data. Once we have done so, we will be able to do preliminary power analysis. In the event that including a peer effects group significantly reduces our statistical power, we will eliminate treatment group D, and focus on an individual level design.