Election 2020

[pbrower2a]

I just got my hands on Nate Silver's The Signal and the Noise (why so many predictions but some don't)It relates probability well, and as I have suggested, being up 5% in a binary election a year before means little, being up 5% a month before the election is huge. It is from 2012, and it relates much other than elections (like sports, poker, and even chess). What it says of electoral leads as a campaign approaches its conclusion is telling.

On page 63, Figure 2-4 shows the probability of a Senate candidate winning (1998 to 2008) with a certain lead (1, 5, 10, and 20 points) at one year, six months, three months, one month, one week, and one day. Because statewide races for President are much like statewide races for the Senate -- with the qualification that Presidential nominees do not usually make appearances where they see themselves losing -- unless they really are losing nationwide.

Time to election  |1 point|5 points||10 points|20 points|
one day............. |...64%|....95%|.....99.7%|.99.999%|
one week........... |...60%|....89%|.......98%|...99.97%|
one month......... |...57%|....81%|.......95%|.....99.7%|
three months..... |...55%|....72%|.......87%|........98%|
six months..........|...53%|....66%|.......79%|.......93%|
one year.............|....52%|...59%|.......67%|.......81%|

(I am going to put this back in my "electoral theory" section because it will remain relevant.

So what conclusions can I draw? You might be surprised that a five-point lead one month before Election Day is no less significant than a twenty-point lead one year before the election. Thus one hears things like Democrats saying "We have a chance of winning West Virginia if everything goes right" and Republicans say that they have a chance of winning Massachusetts... yadda, yadda, yadda. Or is it "Yabba, dabba, doo!" Likewise, being one point ahead on the day before the election is worth almost as much as being five points ahead six months before the election or even ten points ahead  a year before the election.

OK, we all thought in November 2019 that Donald Trump would be the Republican nominee unless the Grim Reaper took him away from us, but how many  of us could have predicted that Joe Biden would be the Presidential nominee? Many liberals were looking for grounds on which to impeach the President, but nobody predicted what those grounds would be, and what the consequences would be upon the 2020 election even if Trump got away with some impeachable behavior

But here we are now, slightly more than two months before the 2020 election. It seems an agonizing eternity for anyone who finds so much about this President, his policies, and his performance insufferable.

I am ready to redo my seat-of-the-pants estimates of Biden and Trump chances based on match-ups alone.  I would need to do some interpolations, and at this I take the dangers of interpolation (much less dangerous than interpolation. Obviously 50-50 is 50% for both.

State data is from here:


https://www.cbsnews.com/news/joe-biden-d...8-16-2020/

August 10.


three months..... |...55%|....72%|.......87%|........98%|

lead  likelihood

0   50    10  87
1   55    11  88
2   59    12  89
3   64    13  90
4   69    14  91
5   72    15  92
6   76    16  93
7   80    17  94
8   83    18  95
9   85    19  96

The interpolation is nearly linear, and that may be inadequate for small leads. This model suggests that even a 3-point edge for Biden at this point (late August) is far from trivial.

Here is a map of the probabilities of a Biden win based upon the edge that one or the other has. Numbers are not electoral votes this time: Data is from August 10, so convention bumps do not appear:



Biden likelihood 0 to 9 (saturation 8 )
Biden likelihood 10 to 19 (saturation 6)
Biden likelihood 20 to 29 (saturation 4)
Biden likelihood 30 to 39 (saturation 4)
Biden likelihood 41 to 49 (saturation 2)
white  -- tie, exactly even

Biden likelihood 51 to 59 (saturation 2)
Biden likelihood 60 to 69 (saturation 4)
Biden likelihood 70 to 79 (saturation 5)
Biden likelihood 80 to 89 (saturation 6)
Biden likelihood 90 or higher (saturation 8 )

It is already two weeks obsolete, because the numbers are based on Senators winning elections based upon their leads at three months (I have done linear interpolation). This is also the last polling data that both

(1) comes from all 50 states,
(2) from the same time, and
(3) from the same source.   

Senatorial and gubernatorial elections for statewide contests for electoral votes by Presidential campaigns. This may be far from a perfect model. Biden has an 80% chance of winning Wisconsin, which this map shows as the most likely tipping-point state. He also has a 69% chance of winning North Carolina and Florida (each), a 64% chance of winning Arizona, a 50% chance of winning Ohio, and a 41% chance of winning Texas .  These six states are dissimilar enough that they could as well be considered independent events. Trump has about seven chances in 1000 to win all six states in question. (I am not considering Iowa, as Biden is not winning Iowa while losing Wisconsin).

At this point, Biden is trying to consolidate the states that he needs or might need. Trump is trying to keep his hope alive in states in which he has as little as a 20% chance of winning.

Another way of putting it: Trump has about as much chance of winning Wisconsin as Biden does of winning Kansas.Joe Biden has an 80% chance of winning Wisconsin. At this point, Trump seems to have about as much chance of losing Kansas (usually an absurd possibility( as he has of winning Wisconsin.