Key excerpt (But it's worth reading the full thing):
But the real value-add of the model is not just in calculating who’s ahead in the polling average. Rather, it’s in understanding the uncertainties in the data: how accurate polls are in practice, and how these errors are correlated between the states. The final margins on Tuesday were actually quite close to the polling averages in the swing states, though less so in blue states, as I’ll discuss in a moment. But this was more or less a textbook illustration of the normal-sized polling error that we frequently wrote about [paid only; basically says that the polling errors could be correlated be correlated between states]. When polls miss low on Trump in one key state, they probably also will in most or all of the others.
In fact, because polling errors are highly correlated between states — and because Trump was ahead in 5 of the 7 swing states anyway — a Trump sweep of the swing states was actually our most common scenario, occurring in 20 percent of simulations. Following the same logic, the second most common outcome, happening 14 percent of the time, was a Harris swing state sweep.6
[Interactive table]
Relatedly, the final Electoral College tally will be 312 electoral votes for Trump and 226 for Harris. And Trump @ 312 was by far the most common outcome in our simulations, occurring 6 percent of the time. In fact, Trump 312/Harris 226 is the huge spike you see in our electoral vote distribution chart:
[Interactive graph]
The difference between 20 percent (the share of times Trump won all 7 swing states) and 6 percent (his getting exactly 312 electoral votes) is because sometimes, Trump winning all the swing states was part of a complete landslide where he penetrated further into blue territory. Conditional on winning all 7 swing states, for instance, Trump had a 22 percent chance of also winning New Mexico, a 21 percent chance at Minnesota, 19 percent in New Hampshire, 16 percent in Maine, 11 percent in Nebraska’s 2nd Congressional District, and 10 percent in Virginia. Trump won more than 312 electoral votes in 16 percent of our simulations.
But on Tuesday, there weren’t any upsets in the other states. So not only did Trump win with exactly 312 electoral votes, he also won with the exact map that occurred most often in our simulations, counting all 50 states, the District of Columbia and the congressional districts in Nebraska and Maine.
I don't know of an intuitive test for whether a forecast of a non-repeating event was well-reasoned (see, also, the lively debate over the performance of prediction markets), but this is Silver's initial defense of his 50-50 forecast. I'm unconvinced - if the modal outcome of the model was the actual result of the election, does that vindicate its internal correlations, indict its confidence in its output, both, neither... ? But I don't think it's irreconcilable that the model's modal outcome being real vindicates its internal correlations AND that its certainty was limited by the quality of the available data, so this hasn't lowered my opinion of Silver, either.
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Notes -
Silver also noticed what I consider the defining difference between Democrats and Republicans: tolerance of dissent.
I think this explains the underrepresentation of democrats on this forum dedicated mostly to American politics. A republican encounters an opinion he disagrees with and is okay with its existence, a democrat encounters such a opinion and seeks a way to prevent its dissemination. Be it be banning a subreddit dedicated to a sitting pro-police POTUS on the grounds it encouraged violence against cops (while leaving pro-BLM and leftist anti-cop subreddits alone), by banning all those who post on dissident subreddits from posting on major subreddits controlled by left-leaning moderators, by denouncing X for allowing non-leftist interpretations of facts to be posted, etc.
Edit: And it was the left-leaning subreddit of ShitRedditSays which was the first to ban people for ideological disagreement, the first subreddit of "pure ideology".
The scant few leftists left on this forum are no exception: still clinging to the "It is a private company" defense for common carriers discriminating against non-leftists, even as "private companies" are not only legally forced service and employ people they would rather not, if they belong to the right demographics, but receive direct orders from the ruling regime about which opinions shouldn't be allowed to be read by consenting readers.
There is a great irony in a major American centre-left talking point being that Republicans are "burning books" for not parents deciding which books are appropriate for elementary school libraries, but government forcing common carriers to prevent a consenting adult sending another consenting adult legal information isn't in anyway contrary to the 1st.
I do wonder if that's part of the shift in the youth vote. Youth tend to be somewhat rebellious. Yet, in almost every online forum, complete ideological purity is demanded, with increasing levels of Obvious Nonsense being declared doctrine, leading to utter hysteria. Any young person who observes that even one item of Obvious Nonsense is, in fact, Obvious Nonsense either learns extremely quickly to somehow suppress their intellect... or they promptly get banned from half the internet.
They say that social death is worse than real death. The internet basically is social life in [Current Year]. Thus, I'd imagine that seeing that even minor observations that Obvious Nonsense is, in fact, Obvious Nonsense gets one banned from half the internet (which is basically akin to social death) is significantly radicalizing, in one way or the other.
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