Our Exit Polls Compared to the Actual Election Results: How did we Do?
On March 21, 2018, elections in 335 municipalities in the Netherlands were held as well as a national consultative referendum on the Intelligence and Security Services Act. Ipsos conducted exit polls in six municipalities (Amsterdam, Rotterdam, Utrecht, Enschede, Weert and Emmen) and a nationwide exit poll for the referendum vote. Based on our exit polls, we gave an indication of the election results and turnout, which was subsequently broadcast by the NOS on national television.
Exit polls for the 6 municipalities
If we compare the results of our exit polls in the 6 municipalities with the actual election results, the performance of the exit polls looks strong. Beforehand, we stated that the average error margin was 1 seat, and that deviations of 2 seats could be possible as well. In practice, any deviation between our exit poll results and the actual seats won by a party is never larger than 1 seat. In terms of the percentage of votes, the maximum deviation between the exit polls and the actual election results is never larger than 2.4 percentage points, and is in most cases less than 1 percentage point.
Exit poll for the referendum
The official result for the referendum will be made public on March 29, 2018, but currently it looks like the no-vote gained a small advantage over the yes-vote. 46.5% voted yes, 49.5% voted no and 4% was registered as a ‘none of the above vote’. The exit-poll registered 49% for the yes-vote, 48% for the no-vote and 3% as a ‘none of the above vote’. Considering the 5% error margin, which we communicated beforehand, the referendum result was in our judgement “too close to call”. This means that our estimate of the No-vote was off by 1.5%, while the estimate for Yes-vote was off by 2.5%. These deviations are well within the margin of error.
The tables below show a detailed comparison between the 7 exit polls and the actual election results in the municipalities and the result for the referendum vote.
More insights about Public Sector
