Authority on crowd sizes questions Phoenix numbers

February 05, 2014

Last Saturday, as an estimated 189,722 people reportedly passed through the gates of the Waste Management Phoenix Open, Steve Doig was busy calculating the attendance of the fourth annual Naam Yoga Super Class held a week earlier in the streets of Mexico City.

The promoters of the yoga event were guessing 20,000 or more. Doig's estimate was 10,000.


What does one have to do with the other? Doig is among the nation's foremost authorities on estimating crowd size and also is a Phoenix-area resident -- an Arizona State University journalism professor and a Pulitzer Prize winner. We asked him whether the Phoenix Open crowd estimates are credible.

"A year or so before the [President Obama] inauguration [in 2009] I was asked pretty much the same questions," he said. "My feeling then, based on some quick estimates of the amount of parking near the course, was the same as now -- the claimed crowd is substantially larger than the actual attendance."

This is not unusual. Doig was asked to estimate the size of the crowd at Obama's inauguration and did so based on a satellite image of the area taken about 30 minutes before the start. His figure, about 800,000, was one million fewer than the government's estimate.

"Whether the crowd is gathering for an anti-war protest, a sports team's victory parade, a golf tournament, a pope's outdoor Mass or the swearing-in of the most powerful man on Earth," he wrote for in advance of the inauguration, "organizational reputations and personal egos are ballooned or deflated by public perceptions of whether the crowd is surprisingly large or disappointingly small."

The golf tournament to which he was referring, he said, was the Phoenix Open. He concedes it would be difficult to get a reliable crowd estimate given that "it's kind of a moving crowd," he said. "The method I have works well for a crowd in a particular location and you can get an aerial view of that crowd, that you can use to measure density."

For its estimates, the Phoenix Open uses 3.2 people per car. "That seems awfully high," Doig said. "Americans just don't do that. I'm sure there are cars with four people, but I suspect lots of them have one or two. I could probably live with two per car."

Doig's interest in crowd estimates began when he was a reporter at the Miami Herald. A pattern has emerged in the estimates he has made over the years.

"I have never seen the one where the organizers have understated how big their crowd is," he said. "As I told the yoga people, you shouldn't be ashamed of getting 10,000 people sitting on yoga mats in in the middle of street."