November 4th, 2009, 12:29am by Sam Wang
Christie (R) won by 4.2%, substantially more than the 1.0% I predicted. On the other hand, Corzine (D) received 44.6% of the vote, quite close to the 44.5% VM-optimized polling average. Looks like it might be Daggett (I) supporters reclaiming the power of their vote.
Was I wrong about NY-23? Only two polls were available. They came before the full impact of Scozzafava (R)’s last-minute endorsement of Owens (D), which evidently worked. It’s a squeaker. Owens won by 4%. This is a lose-lose for Republicans: loss of the seat is a self-inflicted injury by the party’s unreconstructed right-wingers. Full results are here.
Tags: Politics
November 3rd, 2009, 4:02am by Sam Wang
The polls in the Corzine (D) – Christie (R) – Daggett (I) race have been very close. So it’s time for the variance minimization tool that I advocated at the end of the 2008 Presidential race. Using that, I come up with the following conclusions:
Since 10/23 (i.e. the last 10 days), the race has been static. Polls spanning that entire period give
Final margin: Christie over Corzine by 1.0+/-1.0% (68% CI, 16 polls).
3-way outcome: Christie 45.5%, Corzine 44.5%, Daggett 10.0%.
Christie win probability: 83%, i.e. 5:1 odds.
More details, and analysis of the NY-23 race, after the break. [Read more →]
Tags: Politics
June 30th, 2009, 10:08pm by Sam Wang
Last year I recommended a donation strategy that nearly 400 of you followed to give nearly $45,000 to one side (and an unknown amount to the other side). Now that Al Franken is finally on his way to being Minnesota’s junior senator (by 312 votes, a 0.01% margin), was it a good strategy? [Read more →]
Tags: 2008 Election
June 22nd, 2009, 9:32am by Sam Wang
Here’s the latest update from Walter Mebane of U. Michigan. At this point he is quite confident that fraud occurred. He has kindly made data and R scripts available for the curious.
Tags: Politics
June 22nd, 2009, 9:23am by Sam Wang
Iran’s Guardian Council has admitted that apparent turnout exceeded 100% in at least 50 cities. This confirms recent analysis at the University of St. Andrews as well as by David Shor.
Inflated voting is the crudest of fraud, cruder than anything implied by my previous post. At this point statistical analysis is interesting for filling in details and estimating the extent of the fraud.
In other news, Boud Roukema has now reported three of the six most populous voting areas in his analysis have vote totals for Karroubi that start with 7, the anomaly he reported before. All three of these have greater proportions of votes for Ahmadenijad than the other three voting areas.
Tags: Politics
June 21st, 2009, 2:56am by Sam Wang
Current events have completely overwhelmed the relevance of any statistical analysis. But a critical look can still point us toward a better understanding of what happened on Election Day.
Analysis of fraud in Iran 2009 is an unfolding story. In this post I focus on Election Day returns themselves, which suggest: Votes may have been, in some sense, transferred from the minor candidates (Karroubi and Rezaee) to one of the major candidates. This could have been legitimate (that is, voters changing their minds when it came time to vote) or illegitimate (for example, minor-candidate votes being counted for Ahmadinejad). It is currently not known whether enough fraud occurred to flip the election.
Obviously, fraud is not necessarily confined to that suggested by this analysis. For summaries and updates, see David Shor and Fivethirtyeight.com (start with basic returns and poll analysis). [Read more →]
Tags: Politics
June 19th, 2009, 2:48pm by Sam Wang
On June 2-8, one-on-one debates were held between pairs of major candidates. As I posted earlier, these could have shifted opinion. One reader writes:
People watched all of the debates very carefully and the result was actually very bad for AhmadiNejad…[I] am saying that as an Iranian based on what I saw and heard from people during and after the debates. Rezaei did very well in the debates and got popularity (if not votes) specially for his debate with AhmadiNejad.
I wonder if undecideds felt this way.
Tags: Politics
June 18th, 2009, 11:13pm by Sam Wang
Updated with a third possible reason for the discrepancy. -Sam
At a minimum, hundreds of statistically minded people are poring over Iranian election data (see my previous post and these posts). Sorry for my slow start…but let’s roll.
Three general categories of data are currently available for validating the Iranian election: (1) pre-election polls, (2) statistical methods for analyzing standalone voting data, and (3) statistical comparisons with past elections. Categories (2) and (3) are out on the web already, and I’ll comment soon on those efforts.
First, let’s look at some polls. A simple look at pre-election polls leads to the following assessment: National Iranian polls were highly variable and of suspect quality. But within Tehran, polls were more uniform and allow a comparison. Six Tehran polls gave a median lead for Moussavi by 4%. This differs notably from the official tally for the city, Ahmadinejad by 12%. The 16-point discrepancy suggests an anomaly in Tehran and opens the question of whether fraud occurred here – and elsewhere. However, it is also important to note several caveats, including polling uncertainty and possible shifts in opinion following the Ahmadinejad-Moussavi debate on June 3rd.
More after the jump. [Read more →]
Tags: Politics
June 18th, 2009, 8:56am by Sam Wang
In the wake of continuing turmoil over the disputed Iranian election, enough information is available to do some validation of the results. There are several types of information – examples can be seen here and here.
This type of data can be used to look for fraud. Crude fraud can be found by applying Benford’s law, which states that for many categories of data, including vote counts, the first digits of lists of observations are not uniformly distributed (as one would naively expect) but instead skewed toward low values. There are more sophisticated tests as well. Prof. Walter Mebane at the University of Michigan is knowledgeable about such analysis and is applying the methods to the data from the recent Iranian election. In addition to intrinsic peculiarities such as Benford’s law, he is also using 2005 election data as a baseline to help discover unexpected anomalies.
He currently says “”I think the results give moderately strong support for a diagnosis that the 2009 election was affected by significant fraud.” I haven’t had time to go over his analysis, but here it is for interested readers, along with a ZIP file of source code and data. Note that he is still updating his analysis, so regard this as an interim report.
Later on I’ll take a critical look at this and other approaches to detecting fraud, with the idea of arriving at a synthesis – and possible conclusions.
Thanks to David Shor and Andrew Gelman for making this connection.
Tags: Politics
March 10th, 2009, 7:46pm by Sam Wang
For the next month, I’ll be guest-blogging at the New York Times, on Olivia Judson’s site, The Wild Side. Olivia’s off working on her latest book, leaving the writing in various hands – including those of me and my co-author, Sandra Aamodt.
This week we write about intelligence, and how it can be affected by environmental factors. We focus on working memory, which when exercised can improve fluid, problem-solving intelligence. Practice on such a task can raise your IQ by at least four points, on average. Check it out…
Tags: Uncategorized
