Quick update

This is going to be a very short post. I've been again following the latest polls and have updated my election forecast model $-$ nothing has changed in the general structure, only new data coming as the campaigns evolve.

The dynamic forecast (which considers for each day from 1 to 22 May only the polls available up to that point) show an interesting progression for Labour, who seem to be picking up some more seats. They are still a long way from the Tories, who are slightly declining. Also, the Lib Dems are also going down and the latest results seem to suggest a poor result for Plaid Cymru in Wales too (the model was forecasting up to 4 seats before, where now they are expected to get 0).

The detailed summary as of today is as follows.
                mean         sd    2.5% median 97.5%
Conservative 375.109 4.02010949 367.000    376   382
Labour       192.134 3.94862452 186.000    191   200
UKIP           0.000 0.00000000   0.000      0     0
Lib Dem       14.320 2.24781064  10.000     14    18
SNP           50.053 2.12713792  45.975     50    53
Green          0.007 0.08341438   0.000      0     0
PCY            0.377 0.77036645   0.000      0     3
Other          0.000 0.00000000   0.000      0     0

I think the trend seems genuine $-$ Labour go from a median number of predicted seats of 175 at 1st May to the current estimate of 191, the Tories go from 381 to 376 and the Lib Dems from 23 to 14. Probably not enough time to change things substantially (bar some spectacular faux pas from the Tories, I think), though...

I've also played around with the issue of coalitions $-$ there's still some speculation in the media that the "Progressives" (Labour, Lib Dems and Greens) could try and help each other by not fielding a candidate and support one of the other parties in selected constituencies, so as to maximise the chance of ousting the Conservatives. I've simply used the model prediction and (most likely unrealistically!) assumed 100% compliance from the voters, so that the coalition would get the sum of the votes originally predicted for each of the constituent parties. Here's the result.

The Progressive come much closer and the probability of an outright Tory majority is now much smaller, but still...