Unconvinced Yet Influenced: Vaccine Decision-Making in the Shadow of Misinformation

The paper examines how misinformation may shape vaccine decision-making and lead to delay or refusal, even when individuals doubt its truth. It uses an expected utility framework to identify three mechanisms: eroding perceived credibility of authoritative sources, increasing perceived undesirability of adverse effects, and a combination of modest shifts in both. The model shows such behavioural changes can be instrumentally rational under uncertainty rather than representing cognitive failure.