statistics

The Washington Post uses statistics to show human meddling with Iranian vote counts:

The numbers look suspicious. 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. Two such departures from the average — a spike of 17 percent or more in one digit and a drop to 4 percent or less in another — are extremely unlikely. Fewer than four in a hundred non-fraudulent elections would produce such numbers.

As a point of comparison, we can analyze the state-by-state vote counts for John McCain and Barack Obama in last year’s U.S. presidential election. The frequencies of last digits in these election returns never rise above 14 percent or fall below 6 percent, a pattern we would expect to see in seventy out of a hundred fair elections. [WaPo]

That’s on top of observations that intuitively point to something being wrong:

Others have pointed to the surprisingly poor performance of Mehdi Karroubi, another reform candidate, and particularly in his home province of Lorestan, where conservative candidates fared poorly in 2005, but where Ahmadinejad allegedly captured 71 percent of the vote. Eyebrows have been raised further by the relative consistency in Ahmadinejad’s vote share across Iran’s provinces, in spite of wide provincial variation in past elections. [WaPo]