About those general election polls…

Yes, there has been some tightening in the polls. I’ve seen a few maps; 538 shows:


The betting lines show slightly lessened odds for Sec. Clinton:


Clinton was at 4/11 and now she is at 2/5 (the larger the fraction, the worse the odds).

Nate Silver gives a lengthy explanation of why the recent batch of polling changed the model a bit. But while Clinton’s support took a bit of a hit, Trump’s support really didn’t get a bump up.

And so, with the caveats that past Presidential elections are small in number, I’ll just say this: here are the elections in my lifetime. I voted in the last 9 of these. I’ve listed the percentage difference (popular vote) between the winner and the loser:

year difference
1960 0.17
1964 22.58
1968 0.7
1972 23.15
1976 2.06
1980 9.74
1984 18.21
1988 7.72
1992 5.56
1996 8.51
2000 -0.51
2004 2.46
2008 7.27
2012 3.86

Three elections were decided by LESS than 1 percent of the vote, 3 between 1 and 5 percent, 5 between 5-10 percent, and 3 were 10 percent or more (landslides)

But if you look at the “no incumbent in the race” elections, the differences were 0.17, 0.7, 7.72, -0.51 and 7.27 percent.

That is, modern Presidential elections tend to be close, especially when no incumbent is in the race. And so, if the polls really are random, you would not expect one candidate to consistently poll higher than the other. In fact, the margin of error for the support of a given candidate is typically 3-4 points, which translates to a 6-8 percent margin in a two way poll. So even if Hillary Clinton is “really” head by 7 points nationally, you’d expect to see a few polls showing Trump to be slightly ahead. If her lead was really, say, 3 points, you’d expect to see a few polls showing Trump in the lead.

So, while this election is competitive (for now), expect to see a few polls showing Trump head.


July 14, 2016 - Posted by | politics/social, poll | , ,

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