## Saturday, June 20, 2009

### Lucky 7's in the Iranian election.

The number 7 seems to figure prominently in Iranian election results.

On Andrew Gelman's blog, he has some links to other posts by Bernd Beber and Alex Scacco about the Iranian election results. 7 figures prominently.

#1: "We find too many 7s and not enough 5s in the last digit. We expect each digit (0, 1, 2, and so on) to appear at the end of 10 percent of the vote counts. But in Iran's provincial results, the digit 7 appears 17 percent of the time, and only 4 percent of the results end in the number 5. . . ."

#2: "The null hypothesis that the vote count distributions satisfy these distributions is rejected at a significance of p < 0.007, based on the presence of 41 vote counts for candidate K that start with the digit 7, compared to an expected 21.2-22 occurrences expected for the null hypothesis."

So what is it with 7? Quick: think of a number between 1 and 10! People asked that question disproportionately come up with the number 7. Maybe this works not only on Americans, but on Iranians as well. Under pressure to falsify the results (in a consistent manner, so the totals add up), they may be likely to use this heuristic and have "7" pop into their heads.

I don't know anything about Iranian politics worth posting about, but this seems suspicious.