electionpolling – Mid Sussex Election Watch

So who came closest? Analysing Poll Accuracy in the 2024 Mid Sussex Election

Poll	Liberal Democrat	Conservative	Labour	Reform UK	Green	TOTAL DIFFERENCE
ELECTION RESULT	39.6	27.1	17.6	11.1	3.8	N/A
Yougov	43	24.5	17.4	11.3	3.7	6.5
Electoral Calculus	45.3	25.1	18	8.3	3.8	10.9
New Statesman	31.5	24.5	18.7	14.8	5.4	17.1
Electionmapsuk	33.2	24	21.6	15	5	19.3
More in Common	30	28	24	10	6	20.2
Financial Times	31	24.2	24.3	16.2	3.1	24
IPSOS	25	30	28	11	5	29.2
Survation	25.1	29.3	29.8	10.3	4.8	30.7

At Mid Sussex Election Watch we carefully monitored the pre-election opinion polls to get a sense of how the election might turn out in our constituency. Now that the election has happened we thought it might be interesting to go back and look at just how accurate these polls were. We looked at the difference between the actual result and the prediction for each party in each poll, and then calculated the total difference across all the parties for each poll. This proved to be very interesting.

Among the various polls analyzed, YouGov emerged as the most accurate, with a total difference of just 6.5 percentage points across all parties. This poll was particularly spot-on with its predictions for Labour, Reform UK, and the Green Party, with minimal deviations from the actual results. Such accuracy reinforces YouGov’s reputation as a reliable source for gauging public sentiment.

In second place was Electoral Calculus, which had a total difference of 10.9 percentage points. While slightly less precise than YouGov, Electoral Calculus still provided relatively close estimates, especially for the Liberal Democrats and the Green Party.

The other polls showed more significant discrepancies. For instance, More in Common and Financial Times had larger total differences of 20.2 and 24 points, respectively. These polls overestimated support for Labour and underestimated the Liberal Democrat vote share, highlighting the challenges pollsters face in capturing the shifting dynamics of voter behavior.

Interestingly, Survation and IPSOS were the least accurate, with total differences of 30.7 and 29.2 points, respectively. These polls significantly underestimated the Liberal Democrat performance while overestimating Labour’s share. Such variances underscore the inherent uncertainty in polling, where methodological differences and sampling errors can lead to varied results. Funnily enough, it was the Survation poll that Labour consistently chose to use in their election material. (One of their leaflets was headlined, “Poll after poll shows Lib Dems a distant third in Mid Sussex,” without mentioning that actually it was several versions of the same poll that made this prediction…!).

Election Maps UK provided a new perspective with a total difference of 19.3 points. While not the closest, it offered a fairly accurate prediction compared to other polls, highlighting the evolving landscape of polling methodologies.

Conclusion

Yougov has a reputation for accuracy, and in future elections it is certainly worth reflecting their data. Electoral Calculus is also worth a look. As for the others… well, perhaps take their data with a large pinch of salt!

UPDATE FROM MIDSUSSEX.ORG

We have enjoyed bringing you our thoughts and reflections on the General Election campaign, and hope that you have found our content useful. Now that the election has concluded we have migrated all of our content to https://site.sim.onl/mid-sussex-election-watch/. The MidSussex.org domain name will, in due course, be redirected to that page. No further content will be published to MidSussex.org. Any future observations about politics in Mid Sussex will be posted to https://site.sim.onl. Thanks for visiting MidSussex.org over the last few weeks!

EXIT POLL: MID SUSSEX TOO CLOSE TO CALL, BUT PROBABLE LIB DEM GAIN

The exit poll has been published and has stated that the result is “too close to call” in Mid Sussex.

That said, the poll gives a 64% chance of a Lib Dem gain and a 36% chance of a Conservative hold.

At the past five general elections, the exit poll has been accurate to within a range of 1.5 and 7.5 seats.

Final Yougov MRP: Lib Dem Gain

The final Yougov MRP data, published minutes ago, will delight Lib Dem supporters. Yougov’s latest data, published minutes ago, suggests that the Lib Dems will take Mid Sussex with a 43% share of the vote. Yougov put the Conservatives in second place with 24.5%, and Labour in third with 17.4%. This suggests a fairly comfortable win for the Lib Dems and is a significant shift for the Lib Dems from Yougov’s last MRP which had them on 36%, the Conservatives on 28% and Labour on 17%.

This is another significant poll which suggests that the Lib Dems will take the Mid Sussex constituency. To this we say to those who wish to prevent the Tory candidate taking the seat, do not be complacent and vote Liberal Democrat in Mid Sussex.

Final More In Common MRP: Lib Dem Gain

In marked contrast to the final Survation poll, More In Common’s final MRP suggests the Mid Sussex seat will be a Liberal Democrat gain with 30% of the vote. They put the Conservatives in second place with 28% of the vote, and Labour in third with 24%. This is a marked change from their previous poll, in which they put the Lib Dems on 40%, the Conservatives on 31% and Labour on just 16%. This new poll represents a significant weakening of the Lib Dem potential share, and a major strengthening of the Labour vote.

This poll will not be good news for the Lib Dems.

This final poll from More in Common suggests that the result in Mid Sussex could be very tight. There really is everything to play for for the three main parties.

We stand by our advice to vote Lib Dem if you wish to prevent the Tory candidate being elected. This is especially the case if you are considering voting Labour to punish the Conservatives. We maintain that voting Labour in Mid Sussex will only serve to split the Tory opposition vote, which could potentially see the Conservative candidate elected.

Final Survation MRP: Labour Gain

Survation, which has consistently predicted that the Labour Party will take Mid Sussex, have published their final MRP poll. This still shows that Labour will gain Mid Sussex-but by a smaller margin.

They put Labour on 29.8% – down from 30.6% in their last poll. Meanwhile the Conservatives are on 29.3% in their latest research, up from 26.1%. The Liberal Democrats are now on 25.1%, up from 23.6% in Survation’s last MRP.

Survation also state that there is a 51% chance that Labour will win in Mid Sussex, a 37% chance that the Conservatives will win, and a 12% chance that the Lib Dems will take the seat.

It is worth noting that whilst Survation has consistently shown this result, it is very much an outlier (despite but Labour would have you believe); most of the other polls predict a Lib Dem victory, hence why we advise voting Lib Dem if you wish to prevent the Tory taking the seat.

Who’s winning in Mid Sussex #3

Another prediction for the election outcome in Mid Sussex comes courtesy of ElectionPolling.co.uk. This site makes predictions based on a weighted average of polls, and then assumes a uniform swing. This is perhaps not as accurate as some, but as they say, “is still interesting nonetheless.”

Their prediction is Conservative hold but, with a significantly reduced majority of 15,802 (just 134 more votes than Labour).

The full details of the ElectionPolling.co.uk projected result in Mid Sussex are:

This projection gives an insignificant share of the vote to “minor parties” however, which presumably would include Reform UK. If the Reform candidate were to be more successful than predicted here (as predicted by Electoral Calculus, who believe Reform UK could get as much as 11% of the vote), that could draw support away from the Conservatives and secure a Labour victory.

As previous projections have suggested, if a voter were of a mind to attempt to block a Conservative victory, the best bet might be to vote Labour. How much that appeals to affluent Mid Sussex voters – particularly those inclined to support the Lib Dems – remains to be seen.