Right-sizing Incentives

This paper presents results from a field experiment in Nigeria in which expectant mothers were offered cash payments of N2500, N4000 or N10000 conditioned on using formal medical care. A secondary intervention provided some mothers with an information signal about their pregnancy risk. We find highly non-linear effects of conditional payments—most of the incentive effect occurs on the extensive margin, with rapidly diminishing returns to incentive size. We also uncover new spillover effects: showing that incentives increase healthcare use in childhood by index children and by other children in the household. We find largely null effects of the information signal.