‘Several hundred’ vs. 10,000: Debating May Day crowd estimates

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Crowd estimates are notoriously unreliable, with organizers quoting larger numbers and authorities giving more conservative figures. It’s no wonder readers are confused -– or skeptical -– about the numbers reported for events such as this year’s May Day protests in Los Angeles.

In an article Tuesday, an immigrant and labor-rights march downtown was said to have drawn ‘only several hundred people,’ and an Occupy protest was said to have had ‘about 1,000.’

Reporters said the numbers came from their own estimates and from police and security officials.

But readers thought they were too low.

‘One wonders what demonstrations The Times was reporting on for Los Angeles May Day,’ wrote Robin Doyno of Los Angeles.

‘The march north on Broadway alone had more than 2,000 people. The West Wind, one of four directional approaches to downtown, contained at least 50 cars, 30 bikes and two large buses on the approach from Santa Monica to MacArthur Park. And yes, the Labor, Immigration and Occupy communities all did their own thing yet did show up for May Day in numbers much higher than reported.’

Jim Lafferty, executive director of the National Lawyers Guild in Los Angeles, cited a much higher estimate. He said his organization, which describes itself as ‘an effective political and social force in the service of the people,’ had 60 observers among the May Day protests.

‘I am left wondering if the article’s reporters were even actually in Los Angeles yesterday,’ he wrote to The Times. ‘I was present throughout the largest of the two principal immigrant rights marches and rallies, and at the first, and biggest, other reporters on the scene estimated the crowd as ‘about 10,000,’ not ‘only several hundred,’ as The Times reported.’

In their coverage of the protests, the Los Angeles Daily News cited ‘thousands’ of participants, as did KABC-TV and KNBC-TV. However, before the rallies, KCBS-TV reported that 10,000 immigrants-rights marchers were expected.

But how reliable are any of these estimates?

The Times published an article in 2006 about conflicting crowd numbers with the headline, ‘For Those With a Stake, Crowd Size Does Matter.’ According to the article:

Experts say there are scientific ways to gauge crowd size using complex grids, aerial photos, density ratios and flow analysis.

But most police agencies don’t employ such techniques.

Jeff Goodwin, a sociology professor at New York University who has studied crowds, said it would be difficult to get even a remotely accurate crowd count without taking aerial photos that could be broken into sections or grids for careful study.

However, the article said that even the grid technique was imprecise:

Robin Ammon, a professor of crowd management at Slippery Rock University of Pennsylvania, said that even scientific studies -- using techniques based on a certain number of people per square foot -- still produce ‘pure guesstimation.’

This is because ‘a family could be standing very close together and, meanwhile, four to five people are taking up the same amount of space a few feet away,’ he said.

Precise or not, relying on aerial photography is probably not an option for a news article written on deadline.

David Lauter, who is now The Times’ Washington bureau chief, wrote a memo to the Metro reporting staff in 2009 when he was California editor in which he made a similar point:

‘Counting any large number of things is hard to do even when the objects are inert and the counter has no deadline. The job is vastly more difficult when one is trying to count people moving around in a space with unclear boundaries and the question needs to be answered right away. There is a standard method for doing the job. It involves taking pictures of representative parts of the crowd, superimposing a grid on top of the pictures, counting the number of people in several squares of the grid and then multiplying to get the full count. Needless to say, the police, protest organizers or fire officials to whom reporters address their questions about crowd sizes almost never do any of that -- they have jobs to do.’

The memo is included in a January 2009 post by former Readers’ Representative Jamie Gold about attendance at the Rose Parade.

More than three years later, the debate over crowd estimates continues.

--Deirdre Edgar