What Do Measures of Decision-Making Ability Tell Us About Preventive Health Behavior? Evidence from Flu and COVID-19 Vaccination

Abstract

Vaccination is a choice under uncertainty that draws on two distinct abilities: forming beliefs about risks and acting consistently on one’s own preferences. Using the Understanding America Study, I measure the first with cognitive tests of quantitative ability and the second with choice consistency in an incentivized revealed-preference experiment. For influenza (2014–2026), neither predicts vaccination on average, but receipt falls over time especially post COVID among the least consistent adults, most sharply among Republicans, and the consistency gap grows most among adults with fewer chronic conditions, groups likely to perceive less risk. For COVID-19 (2021), quantitative ability predicts who got vaccinated earlier. The gap opens as each age group becomes eligible and reaches a similar size in each, so access mainly affects its timing. Higher-ability adults held more favorable beliefs about vaccine safety and effectiveness before most could get a dose, and these beliefs account for about 60 percent of the gap. This points to prosocial and norm-based messages for familiar vaccines, since they do not rely on perceived personal risk, and to early, clear safety information for new ones.