# Vaccine Incentives Harm Intrinsic Motivation: Evidence From a Priming Experiment

## TL;DR

Offering money for vaccination can backfire by reducing people's natural motivation to get vaccinated, especially among certain groups.

## Contribution

The study provides experimental evidence that monetary incentives can harm intrinsic motivation and perceptions of vaccine safety.

## Key findings

- One in seven vaccine-hesitant adults declined vaccination after being primed with a monetary incentive.
- Priming reduced perceived vaccine safety by 9 percentage points and prosocial attitudes by 10 percentage points.
- Negative effects were stronger among men, minorities, and those with low vaccine trust.

## Abstract

Monetary incentives for vaccination may undermine intrinsic motivation, but evidence on this effect remains scarce. We conducted an experiment among 513 vaccine‐hesitant adults to test whether priming individuals with a monetary incentive reduces their willingness to vaccinate against COVID‐19. Our findings show that one in seven were willing to vaccinate without an incentive but declined the vaccine when asked to consider a payment. Additionally, priming participants lowered their perceptions of vaccine safety by 9 pp and prosocial attitudes toward vaccination by 10 pp. These negative effects were concentrated among men, racial and ethnic minorities, and participants with lower preexisting trust in the vaccine. Our results highlight an unintended consequence of vaccine incentives.