We’ve all seen the job
approval polls and at first blush they appear like a catastrophe. How did that happen, so quickly after
President Trump was sworn in? Recall
though that these are the same pollsters/clowns who wrongly gave Hillary Clinton (on Election
Eve) a ~90%
chance of winning. On the other hand,
this site was
among a rarest prominent
voices to stick their reputation
on the line to repeatedly forewarn that ALL the mainstream pollsters were wrong in what they claimed was a sure thing. Of course they are still wrong here, in how
they are deceiving the American (and
global) public that the initial job approval ratings mean anything relevant. Don’t fall for it, as you and Hillary Clinton
fell for it last autumn. Pollsters peddle
appalling work, while pretending to be scientifically accurate.
Independent voters haven’t
suddenly -a day after the election- decided to disapprove of President
Trump. They are far more mature. But we know exactly which political quadrant
of the country is lashing out here. And
even if they weren’t, the polls right now simply provide no insight and contain
an embarrassingly 2x or 3x as high actual margin of error than what they
presume. In our case the approval poll
estimates should be biased significantly
in favor of President Trump (closer to 50% actual job approval) solely based
on the most unchanging current confidence interval.
The other issue is that the
main attention for these polls is how it might eventually map to one’s 2020 re-election
odds. Is President Trump a two-termer or
not? And here the initial job approvals
(unless they sink well below 30%) have little to do with re-election
probabilities! Clearly the state of the
economy in a couple years and the qualifications of whoever the emerging Democratic
contender is, will jointly bear on the actual re-election probabilities. But they will also cause Americans then to reassess
President Trump’s job performance accordingly.
So the main variable that
matters, in the context of this job approvals article, is what the job
approvals value is in a couple years. Don’t
waste your time dreaming. But know that Presidents
who start with low job approvals, as we have here, will generally see the
benefits on mean-reversion. Surely there
could be something appalling that President Trump does on his own to self-inflict
a mortal wound in his own chances, but barring such ludicrousness, count him in
as a strong contender for 2020.
It is imperative to this analysis
to appreciate that continuously from President Roosevelt in the late-1930s, to the
mid-1970s, presidents almost always become re-elected. Didn’t matter much about their actual
performance! But progressively, since the 1970s, American voters have changed and
are now much choosier. Surely they
expect results, but they also give presidents a fair chance. Disregard the lunacy you might see at a
weekend anti-Trump rally (or from Kathy Griffin), most Americans are giving the
President a real chance and he will have some positive surprises as well (and
some avoidable boo-boos).
But a probability model to predicting
re-election based on the various information discussed so far, should incorporate
both the job approval a couple years down the road (and not today’s in any way), as well as the recent
several presidential relationships between these future job approvals and the
re-election results.
Thankfully there were some
recent losses from incumbents (most recently President Bush in 1992) to gauge
the model strength. See the chart below
for prediction of re-elections, using just the 3rd year job
approvals for the past dozen applicable presidents, and stretching back nearly
80 years. Note that for visual simplicity, data are randomly scattered above and below the blue-color model curve.
With President Trump ricocheting high 40s%, we might imply just greater than 50% or so chance of re-election (coincidentally again just better than the odds that established, gambling bookies have for him). But such a model isn’t the best-fit
anyway. It has a R2 (the entropy,
or the generalized calculations) of only in the 0.2s (on a fit scale of 0, to
1).
The strongest version is to
incorporate the political changes across the decades, of what these job approvals
might suggest. There we get a much
better fit (by a magnitude of 2), with a R2 that is now in the
high 0.8s! Additionally, the confusion
matrix shown below provides an extraordinary degree of predictive accuracy (minimize
all errors) with only one error in the past 12 elections! That’s a much better record than Nate Silver
and the other fellows, who typically have had terrible election forecasting
results.
Predicted re-election win
|
Predicted re-election loss
|
Type-2 accuracy
|
|
Actual
re-election win
|
9
|
0
|
100%
|
Actual
re-election loss
|
1
|
2
|
67%
|
Signal
accuracy
|
90%
|
100%
|
92%
|
July & October 2017 addendum:
The @DNC are most bloodthirtsy in 30 years. May not matter for 2020 (Bush had high #JobApproval). Just don't loathe. https://t.co/twcyNbkS3g pic.twitter.com/WVxQX4yv16— Statistical Ideas (@salilstatistics) July 6, 2017
complex math modeling can hinder efforts to glean insights (e.g., seeing who gained from stock rally) https://t.co/jog661Z470 ht @ColinCBarr pic.twitter.com/jaz6O7VuQk— Statistical Ideas (@salilstatistics) September 15, 2017
No comments:
Post a Comment