Online and live-caller polls disagree about Biden’s lead over Trump
The pattern muddies the waters for election forecasters in 2020
Hello loyal readers!
My computer is ticking away on some election models so I thought I’d send you a little note while it finishing thinking.
I have spent a lot of time collecting state-level polling data for the 2020 presidential race over the past week or so. In all my rummaging of PDFs and news reports, I have noticed an interesting, if familiar, pattern: polls conducted online are showing very different numbers from polls conducted over the phone with a live interviewer.
Online polls have tended to be much more favorable to Joe Biden. In Florida, for example, the average of live-caller polls has Donald Trump up one point over (and inside the margin of error with) Biden, but polls conducted online have Biden up by 4. One firm even conducted two Florida polls a month apart, once each via phone and web, and found a 6-point difference in Biden’s projected margin of victory.
These differences sound small, but they are quite large when added up. Accounting for the fact that state-level po…
