Mystery of the Lagging Ballots (chapter summary)

Returned mail-in ballots from Republican voters consistently exhibited longer turnaround times than those from Democrats, with mean return intervals remaining significantly higher even after controlling for county, voter age, and application type. Like the return rate disparities, the turnaround disparity is larger for earlier applicants. Statistical controls account for only a small fraction of the gap, and cumulative return curves show Democrats’ ballots accumulating more rapidly throughout October across virtually every county. The persistence and breadth of these lag patterns raise unresolved questions as to whether they reflect behavioral differences in voter urgency or external impediments affecting ballot delivery and processing.