Table 1.
Financial incentive strategies.
| Financial Incentive | Baseline | Week 2 | Week 4 | Week 6 | Total Study Payments | Behavioral Rationale |
|---|---|---|---|---|---|---|
| Constant | $0.25 | $0.25 | $0.25 | $0.25 | $1.00 | Control condition |
| Increasing | $0.10 | $0.20 | $0.30 | $0.40 | $1.00 | Sunk cost bias and loss aversion [23,24] |
| U-shaped | $0.40 | $0.10 | $0.10 | $0.40 | $1.00 | Larger incentives more effective than smaller incentives [25] |
| Surprisea | ($0.20) | ($0.10) | ($0.30) | ($0.40) | $1.00 | Lottery-based incentive [26] |
| Self-select | participants chose preferred incentive arm | $1.00 | Giving control enables intrinsic motivation [27] | |||
a
Participants in the surprise arm were informed of the total potential incentive amount, but not the disbursement amounts at each timepoint.