- Researchers estimate the effects of Ohio’s lottery program Vax-a-Million on COVID-19 vaccination rates by comparing it to a “synthetic control” composed of eight other states. We find a statistically insignificant 1.3% decrease in the full vaccination rate in Ohio at the end of the lottery period. https://www.cambridge.org/core/journals/journal-of-experimental-political-science/article/did-ohios-vaccine-lottery-increase-vaccination-rates-a-preregistered-synthetic-control-study/07720E0BB974962FE4547FF2BCC71CAC#article 14 comments science