Assumptions about behaviour influence the policy preferences of public officials

Public officials often aim to change people's behaviour to achieve policy goals. Policy design and behavioural perspectives suggest that individual factors such as officials' assumptions about behaviour — or implicit theories — can influence officials' policy choices. This pre-registered survey study examines how assumptions about cooperation, behavioural malleability, and self-control influence policy preferences among 1,015 public officials in the Netherlands. Results show that officials who believe in high levels of cooperative behaviour and behavioural malleability support more government intervention, while assumptions about self-control have no significant effect. Additionally, a quasi-experiment with an information-based intervention led officials to update their assumptions towards greater accuracy.