2 elections where the final polls got the result badly wrong. Each deep dive sets out what the polls said, what happened, what the official inquiries and the pollsters found, what our own data shows, and what the pollsters changed afterwards. Every one of these misses is in the record our forecasts learn from.
How far out the final polls were
The error on the lead between the top two: the final polls' average against the result, in points.
RN and allies 36.1, NFP 28.4 (first round); RN bloc 170–250 seats, largest group in every final projection
Result
RN and allies 33.2, NFP 28.0 (first round); seats NFP 178, Ensemble 156, RN and allies 142
The first-round polls were close (RN bloc 36.1 against 33.2, NFP 28.4 against 28.0), but every final seat projection made the RN bloc the largest group with 170 to 250 seats, and it came third with 142. More than 200 withdrawals between the rounds and unusually disciplined voters broke the transfer patterns the projections were built on.
Chirac 19.7, Jospin 17.8, Le Pen 13.0: Jospin safely second
Result
Chirac 19.9, Le Pen 16.9, Jospin 16.2
The final polls had Jospin on 17.8% and Le Pen on 13.0%; Le Pen took 16.9% and knocked Jospin (16.2%) out of the run-off. Every institute understated the far right while the outgoing left's smaller candidates were overstated, and the Commission des sondages pointed to telephone samples, cautious political weighting and institutes smoothing their published figures.
For each country we measure how far the final polls missed at past elections. We take half the average miss off today's polls only where that would have made past forecasts better, testing each election without knowing its result; elsewhere the polls stand as published. Every forecast then runs thousands of simulated elections with polling errors the size of these, so a miss like the ones above is inside our ranges, not a surprise. Polls against results, every election · Our forecast record · Pollster leaderboard
France · 30 June 2024
2.5 pts