Archive for votes

it figures [the return]

Posted in Kids, pictures, Statistics with tags , , , , , , , , , , , , , , , on December 23, 2024 by xi'an


An article in The Guardian on 03 December pointed out the fallacy of reporting landslides and massive victory of Donald Trump

  • he did not win the majority of the votes, albeit getting more popular votes than Kamala Harris
  • his margin of victory is a mere 1.6 percent
  • the 312 votes in the electoral college are par both Trump’s result in 2016 (304) and Biden’s in 2020 (306)
  • he won the blue wall states by 231,000 votes total, hence would have lost had only 116,000 voters (0.7% of the votes) switched.

While Nate Cohn of The New York Times reflected on the poll strengths and misses, since

  • polls predicted shifts in several voting groups towards Trump
  • they underestimated him by about two percentage points, which is the average poll error along years
  • and they did not do well at predicting turnout in Democratic districts

borderline call to voters’ registration

Posted in Kids, pictures, Travel with tags , , , , , , , , , on March 30, 2024 by xi'an

Georgia on my mind

Posted in Books, Kids, Statistics, Travel with tags , , , , , , , , on May 12, 2021 by xi'an

The riddle of this week was inspired by the latest presidential elections when one State after another flipped the winner from Trump to Biden. Incl. Georgia.

On election night, the results of the 80 percent who voted on Election Day are reported out. Over the next several days, the remaining 20 percent of the votes are then tallied. What is the probability that the candidate who had fewer votes tallied on election night ultimately wins the race?

Assuming many votes, perfect balance between both candidates (p=½), and homogeneity between early and late ballots, the question boils down to the probability of a sum of two normals, X+Y, ending up being of the opposite sign from X, when the variances of X and Y are α and 1-α. Which writes as the expectation

2 \mathbb{E}_\alpha[\Phi(-X/\sqrt{1-\alpha})]

equal to

\frac{2}{2\pi}\left(\frac{\pi}{2} + \arctan\{\sqrt{\alpha/(1-\alpha)|}\}\right)

which returns a probability of about 0.14 when α=0.8. When looking at the actual data for Georgia, out of 5 million voters, at some point 235,000 ballots remained to be counted with Trump on the lead. This means an α about 0.05 and implies a probability of 7% (not accounting for the fact that the remaining mail-in-ballots were more favourable to Biden.)

another electoral map

Posted in Books, Kids, R, Statistics, University life with tags , , , , , , , , , , , on November 11, 2020 by xi'an

la peste gagne…

Posted in pictures with tags , , , , , , on May 27, 2019 by xi'an

(Source: Le Monde, 27 Mai 2019)

And in a more balanced presentation:

(Source: Le Monde, 27 Mai 2019)