Parts Greater Than Their Sum : Randomized Controlled Trial Testing Partitioned Incentives to Increase Cancer Screening

We present a simple behavioral strategy based on Prospect Theory that maximizes the impact of financial incentives with no additional cost. We show how the partition of a single incentive into two smaller incentives of equivalent total amount produces substantial behavioral changes, here demonstrated in the context of colorectal cancer screening. In a randomized controlled trial, eligible patients aged 50-74 (N=1652 patients) were allocated to receive either one EUR10 incentive (upon completion of screening) or two EUR5 incentives (at the beginning and at the end of screening). We show that cancer screening rates were dramatically increased by partitioning the financial incentive (61.1%), compared to offering a single installment at the end (41.4%). These results support the hedonic editing hypothesis from Prospect Theory and underline the importance of implementing theoretically grounded healthcare interventions. Our results suggest that, when patient incentives are feasible, they should not be offered at once, but rather healthcare procedures should be framed as multistage events with smaller incentives offered at multiple points in time