Disentangling Enforced and Voluntary Behaviour Change During the COVID-19 Pandemic in the Netherlands

Background:Effective pandemic mitigation relies on population behaviour change. To understand how to achieve this, it is important to not only consider restrictive policies that enforce behaviour change but also consider voluntary responses to changes in pandemic severity and behavioural advice. Aim:The current study investigates to what extent change in protective behaviour during the Covid-19 pandemic in the Netherlands can be attributed to self-guided behaviour change (in response to changes in pandemic severity), adherence to government behavioural advice, or to compliance with restrictive policies.Methods:We analysed survey and mobility data on 7 protective behaviours from 2020–2023. Using time-series and mixed-effects models, we examined associations between pandemic severity (hospitalisations), government behavioural advice, and restrictive policies with these behaviours. Control variables included seasonality, pandemic duration, and demographic characteristics. Results:Pandemic severity was consistently found to be associated with increases in protective behaviour, while the impact of behavioural advice and restrictive policies varied. Moreover, the estimated impact of behavioural advice and restrictive policies was substantially reduced when including pandemic severity in the models.Conclusion:The consistent association between pandemic severity and protective behaviours indicates that people changed their behaviour in order to protect themselves and others, even without government advice or restrictive measures. Behaviour change could be further promoted through behavioural advice and/or restrictive policies, although the estimated impact of these approaches varied substantially between target behaviours. These results highlight the importance of voluntary behaviour change and accounting for type of behaviour change when designing and evaluating mitigation policies.