Less carrot more stick? Investigating rewards and deposit contract financial incentives for physical activity behavior change using a smartphone application: randomised controlled trial (Preprint)
Authors: de Buisonjé David Richard , Reijnders Thomas , Cohen Rodrigues Talia R , Prabhakaran Santhanam , Kowatsch Tobias , Lipman Stefan A , Bijmolt Tammo H A , Breeman Linda D , Janssen Veronica R , Kraaijenhagen Roderik A , Kemps Hareld M C , Evers Andrea W M 
Published: April 2022

BACKGROUND

Financial incentive interventions for improving physical activity have proven to be effective but costly. Deposit contracts (a type of incentive in which participants pledge their own money) could be an affordable alternative. In addition, deposit contracts may have superior effects by exploiting the power of loss aversion. Previous research often operationalized deposit contracts through framing a financial reward as a loss (without requiring a deposit) to mimic the feelings of loss involved in a deposit contract.

OBJECTIVE

This study aims to disentangle the effects of incurring actual losses (through self-funding a deposit contract) and loss framing. We investigated (1) whether incentive conditions are more effective than a no-incentive control condition, (2) whether deposit contracts have lower uptake than financial rewards, (3) whether deposit contracts are more effective than financial rewards, and (4) whether loss frames are more effective than gain frames.

METHODS

Healthy participants (N = 126) with an average age of 22.7 years participated in a 20-day physical activity intervention. They downloaded a smartphone application that provided them with a personalised physical activity goal and either required a €10 deposit upfront (which could be lost) or provided €10 as a reward, contingent on performance. Daily feedback on incentive earnings was provided and framed as either a loss or a gain. We employed a 2 (incentive type: deposit vs reward) x 2 (feedback frame: gain vs loss) between-subjects factorial design with a no incentive control condition. Our primary outcome was the number of days participants achieved their goal. Uptake of the intervention was a secondary outcome.

RESULTS

Overall, financial incentive conditions (M = 13.10 days) had higher effectiveness than the control condition (M = 8.00 days), p = .002, ηp2 = .147. Deposit contracts had lower uptake (61.7%) than rewards (100%), p = <.001, V = .492. Furthermore, two-way ANCOVA showed that deposit contracts (M = 14.88 days) were not significantly more effective than rewards (M = 12.13 days), p = .166. Unexpectedly, loss frames (M = 10.50 days) were significantly less effective than gain frames (M = 14.67 days), p = .007, ηp2 = .155.

CONCLUSIONS

We found that financial incentives help increase physical activity, but deposit contracts were not more effective than rewards. Although self-funded deposit contracts can be offered at low cost, low uptake is an important obstacle for large scale implementation. Unexpectedly, loss framing was less effective than gain framing. Therefore, we urge for more research on their boundary conditions before using loss framed incentives in practice.

CLINICALTRIAL

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