# **5.b The role of risk perceptions**

Individuals form their risk perceptions about the pandemic using the information set available to them and their individual circumstances, like their age, gender or education. As our analytical framework indicates, these risk perceptions, mediated by other factors such as trust and social norms, drive vaccine behavior. While it is out of the scope of this paper to provide a detailed analysis of the formation of risk perceptions, the data allows to have a preliminary look at the relationship between vaccine acceptance and risk perceptions about COVID-19 infection. The survey we use includes a question on the likelihood that a person of the same age and in the same community as the respondent becomes sick from COVID-19. We create a dummy variable that indicates whether a respondent stated that this event was “very” or “extremely likely”. We call this variable the “perception of high risk of infection”. Columns 1 and 2 of Table 3 look at the correlations between this variable and individual characteristics and beliefs. Men, people living in rural areas, and younger individuals have all a perception of a lower risk of becoming sick from COVID-19. People in good health perceive their risk to be low as well. Interestingly, individual beliefs appear to be associated to risk perceptions in an unusual direction: individuals who have higher trust in government health authorities and those who believe that most individuals in their community will accept the vaccine also report _higher_ infection risk perceptions (Table 3, Column 2). While this correlational analysis does not allow to establish the exact causal nature of this relationship, it suggests that individuals who do not trust health authorities and who do not believe that the community in which they live will accept the vaccine may systematically underestimate the actual spread of the disease and the severity of the pandemic. Misinformation could be a potential explanation, as Roozenbeek et al. (2020) find that individuals who distrust scientists are more susceptible to misinformation about the pandemic.

When introduced as a separate, independent regressor in equation (1), this “perception of high risk of infection” variable is associated with a 9 percentage points higher probability of accepting the vaccine (Table 3, column 3). The coefficients associated to the stringency index and the personal knowledge of a positive COVID-19 case in that same specification remain significant but decrease slightly in magnitude. A similar pattern is observed if risk perceptions are interacted with the stringency index (Table 3, column 4).

These results confirm the relevance of risk perceptions as highlighted by our analytical framework. Government policies and individual experience of the pandemic have an effect on vaccine acceptance through risk perceptions. However, the fact that both variables still have a considerable explanatory power suggests that this particular measure of risk perception does not capture fully the risk perceptions that individuals have in mind. Other dimensions of risks beyond individual infection may be driving vaccine acceptance.

# **5.c Trust and social descriptive norms**

Information and individual circumstances form risk perceptions, which are in turn mediated by trust and social norms as individuals decide on accepting the vaccine or not. The different specifications of Table 4 explore the role that mediating factors such as social descriptive norms (the number of people in the community that the individual believes are going to get the vaccine) or trust in government health authorities play in individual vaccine acceptance. Column 1 presents a simple specification in which both variables are included as independent regressors. Both are strongly and positively correlated with vaccine acceptance. The more individuals believe vaccine acceptance to be the prevalent social norm in their community, the higher their own willingness to get the vaccine. For every additional percentage point of believed acceptance in the community, individual vaccine 13