Evidence from a statewide vaccination RCT shows the limits of nudges

Effect of Text Messaging and Behavioral Interventions on COVID-19 Vaccination Uptake

“…A large trial in Rhode Island conducted at a similar time during vaccine rollout showed a null effect from behaviorally informed text messaging when compared with no outreach. 25 A large trial by Milkman et al 10 of text messaging before a primary care appointment to encourage influenza vaccination showed that endowment-framed messaging had the highest response rate, with a similar magnitude of effect to our messaging.…”

Can financial incentives and other nudges increase COVID-19 vaccinations among the vaccine hesitant? A randomized trial

“…As that study was conducted in February 2021, before vaccines were available to the general public and when the demand for vaccines outpaced supply, both nationwide [47] and in the study site of Los Angeles [48] , it may also hold limited applicability for vaccine hesitant populations. The other study, compared “ownership” framed messages, in some conditions supplemented with other information about vaccines, relative to no messages and found no impact on vaccination rates [49] . This sample, which was made up of unvaccinated adults in Rhode Island in late May to June 2021, after more than a month of eligibility, was most similar to ours in focusing on the vaccine hesitant population.…”

Increasing COVID-19 vaccination intentions: a field experiment on psychological ownership

“…Moreover, the tangible medium (letter vs text messages), trust in the messenger (Everett et al, 2021) and the timing might play a role. For instance, other studies have shown null results for text messages targeting hesitant people (Rabb et al, 2021). In addition to low-touch approaches such as behaviorally informed communication, there is a need for other methods like incentives and policy measures such as testing (Thunström et al, 2021).…”