Voting by Mail and Ballot Rejection: Lessons from Florida for Elections in the Age of the Coronavirus

The COVID-19 pandemic and its concomitant need for social distancing have increased the attractiveness of voting by mail. This form of voting is nonetheless not a panacea for election administration in the time of a public health crisis, as a widespread move to ballots cast by voting by mail risks exacerbating existing inequities in mail-in ballot rejection rates across voters and jurisdictions. This motivates our examination of the roughly 9.6 million and 8.2 million ballots cast in the 2016 and 2018 general elections in Florida, respectively, including over 2.6 million vote-by-mail (VBM) ballots cast in each. Using a selection model that analyzes all ballots cast and those VBM ballots not counted in Florida in these two elections, we find that younger voters, voters not registered with a major political party, and voters in need of assistance when voting are disproportionately likely to have their VBM ballots not count. We also find disproportionately high rejection rates of mail ballots cast by Hispanic voters, out-of-state voters, and military dependents in the 2018 general election. Lastly, we find significant variation in the rejection rates of VBM ballots cast across Florida's 67 counties in the 2018 election, suggesting a non-uniformity in the way local election officials verify these ballots. As interest in expanding mail voting swells as a consequence of the novel coronavirus, protecting the rights of all voters to participate in electoral politics requires a characterization of the correlates of VBM ballot rejection with an eye toward considering how disparities in ballot rejection rates might be rectified.