Time Preferences and COVID-19 Vaccination Hesitancy – Center for Health Decision Science

Vaccine hesitancy is affected by many factors, including individuals’ willingness to trade-off harms and improvements likely to occur now versus in the future. Arthur Attema explored these time preferences in a CHDS seminar, based on a global survey that investigated individual attitudes toward COVID-19 vaccination. Attema is Associate Professor of Health Economics and Utility Theory at the Erasmus School of Health Policy and Management in Rotterdam.

Attema models vaccine hesitancy as a function of delayed benefit and willingness to take risks. Using the VaxPref database, a rich dataset with over 50,000 participants across 22 countries, he explores the amount of present bias, which is the tendency to prefer smaller immediate payoffs to larger delayed payoffs, and the rates at which individuals discount future effects in making current decisions. Individuals were classified as acceptors, hesitators, or rejectors based on their response to a question on their COVID-19 vaccination status. They were also asked about their willingness to trade financial gains in the present for larger financial gains in the future and their attitudes towards health risks.

The results show that time preferences moderately effect vaccination behavior, with notable differences across countries. Discount rates vary and there is little evidence of present bias in most cases. Vaccination strategies often involve costs incurred in the present while benefits (reduced likelihood of infection and illness) may only accrue far in the future. Individuals with higher discount rates likely have lower demand for vaccines if the immediate benefits are small. In addition to protection against illness, these immediate benefits may include greater access to activities (such as travel or events) that are otherwise restricted to reduce the spread of infection. Individuals with lower discount rates may be willing to wait a long time for a safer or better vaccine to be approved. He finds that vaccine-hesitant respondents have higher discount rates than vaccinated individuals, who in turn have higher rates than refusers.

Attema’s team also assessed risk attitudes towards COVID-19 vaccines and generic side-effects. He found that individuals who are vaccine hesitant or refuse to be vaccinated tend to be less likely to take health risks, while vaccinated individuals tend to be more risk-loving. This finding implies that the surveyed individuals felt that the risk of side effects of the vaccine were more important than the risk of COVID-19 infection if unvaccinated. Attema hopes to expand on this research by incorporating multivariate preferences and higher order risk preferences, including temperance and prudence, as well as ambiguity.

Learn more: Read the publication, Public Preferences for Vaccination Campaigns in the COVID-19 Endemic Phase: Insights from the VaxPref Database
Learn more: The COVID-19 Vaccine Preferences Project