What will the average number of measles cases be during Trump's term?

Measles is one of the most outbreak-prone infectious diseases in the U.S. because a large share of the population still lacks recent immunity gaps, and the disease can spread quickly in under-vaccinated communities. Over a four-year presidential term, the average number of cases is likely to be driven less by any single year and more by whether there are one or two sizable outbreaks, which can push the mean sharply higher even if most years remain relatively calm. Political and social factors matter here: if vaccine skepticism remains elevated or public health messaging weakens, the baseline risk of recurring outbreaks rises meaningfully. That said, measles is also a disease for which rapid containment is possible, so the difference between a bad and a moderate outcome can be substantial.

Compared with the current market price, I think the market is leaning too far toward the No side if the question is essentially whether the Trump administration will preside over a relatively high average measles burden. The market may be assuming that measles will remain a low-incidence disease because the U.S. has strong infrastructure and outbreaks are usually localized. That is a reasonable caution, but it may underweight the fat-tail nature of measles risk: a small number of outbreaks can dominate the term average, and policy or rhetoric that reduces vaccination uptake can have delayed but real effects. My probability is still well below a coin flip because containment and existing immunity remain powerful counterforces, but I do think the Yes side is somewhat more likely than the 35% market price implies.