Discussion
Some experts have warned that financial incentive policies are likely to “backfire” by reducing interest in the COVID-19 vaccine [Contrary to the critics’ concerns [The effects of the relatively large and small monetary amounts were similar; although the $1,000 payment yielded a slightly stronger effect than the $200 payment, the difference was not statistically significant. While the larger amount was associated with a higher proportion that wanted to vaccinate compared with the smaller amount, the difference may reflect diminishing marginal returns relative to increases in payment size. Various hypotheses could explain this finding and more research is needed to understand why the different payment amounts had similar effects. However, diminishing returns between smaller and larger incentive amounts have also been observed in other vaccination research and in lower income populations [Research on several behaviors, including vaccination, has suggested that educational interventions often fail [We can only speculate as to why financial incentives may have a positive psychological effect during the COVID-19 pandemic. Although some unvaccinated Americans are adamantly opposed to vaccination, many who are unvaccinated may be better described as apathetic or ambivalent [The financial incentive policies may also decrease the perceived and actual financial costs of vaccination that are disproportionately burdensome for lower income individuals. For example, COVID-19 vaccination sites frequently require appointments that are offered during standard working hours and most employers still do not provide paid time off from work for vaccination [Prisons, which disproportionately incarcerate lower income individuals and individuals from racial and ethnic minorities, have offered financial incentives for COVID-19 vaccination while removing several logistical barriers. For example, several Pennsylvania prisons provided $25 commissary credit to buy clothing, food, or other items [