… Had Yougov done well, I could use them as an example of the success of MRP, and political polling more generally, so I should take the hit when they fail. It looks like Yougov was off by about 4 percentage points (or 8 percentage points if you want to measure things by vote differential). It will be interesting to how much this difference was nonuniform across demographic groups.
The difference between survey and election outcome can be broken down into five terms: CONT.
Andrew Gelman, Columbia U.