Fig 1: Errors in estimates of vaccine uptake.
From: Unrepresentative big surveys significantly overestimated US vaccine uptake
a, Estimates of vaccine uptake for US adults in 2021 compared to CDC benchmark data, plotted by the end date of each survey wave. Points indicate each study’s weighted estimate of first-dose vaccine uptake, and intervals are 95% confidence intervals using reported standard errors and design effects. Delphi–Facebook has n = 4,525,633 across 19 waves, Census Household Pulse has n = 606,615 across 8 waves and Axios–Ipsos has n = 11,421 across 11 waves. Delphi–Facebook’s confidence intervals are too small to be visible. b, Total error \({\overline{Y}}_{n}-{\overline{Y}}_{N}\). c, Data defect correlation \({\hat{\rho }}_{Y,R}\). d, Data scarcity \(\sqrt{(N-n)/n}\). e, Inherent problem difficulty σY. Shaded bands represent scenarios of ±5% (darker) and ±10% (lighter) imprecision in the CDC benchmark relative to reported values (points). b–e comprise the decomposition in equation (1).
