Estimate 3.1 Million Came To 50th Annual Air & Water Show

Hey, maybe they all came out to see Bill Murray's parachute jump. Attendance figures cited by the city of Chicago for last weekend's 50th Annual Chicago Air & Water Show invited skepticism, and called attention to the imperfect (cough) science of gauging crowd attendance at air shows and other large public events.

The Chicago Tribune reports city organizers estimate around 3.1 million people visited the show from Friday afternoon through Sunday... far above the usual 2 million visitor average the show has garnered in years past, when it was only a two-day affair.

That's an impressive number... but many say it's unlikely the show attracted an extra 1.1 million attendees for that extra half-day. By comparison, officials point out, the city's world-renowned Taste of Chicago festival pulled in 3.56 million people over 10 days.

Over-inflated attendance numbers are nothing new for air shows... but the matter isn't necessarily one of nefarious intent. Organizers in Chicago admit the method for calculating attendance numbers at large public events like the waterfront air show is an imperfect science, at best.

Cindy Gatziolis, spokeswoman for the Mayor's Office of Special Events, says aerial photographs of the crowds were compared against mathematical formulas used by police to estimate known crowd levels in a number of areas. Those numbers are then increased to account for new arrivals, who add to the crowd as others head home.

"We do see constant flow coming in and out," Gatziolis said.

And if Chicago's estimates are off... well, it wouldn't be the first time that's happened. Initially, officials said over a million people attended the 1979 papal mass by Pope John Paul II in Grant Park; months later, aerial photos showed the crowd to be somewhere between 65,000 and 350,000 people. That large spread is a prime example of how hard it is to estimate crowd levels, officials say.

In another infamous example, the National Park Service took flak for saying only 400,000 or so people attended the 1994 "Million Man March" on Washington, DC. A study by the Boston University Center for Remote Sensing later said the crowd was somewhere around 873,000, with a 15 percent margin of error.

Amidst allegations of deliberate undercounting for the racially-charged event, the Park Service stopped trying to count crowd levels.

Though questions will likely remain for some time regarding how many really attended Chicago's air show, there are signs attendance was definitely up. Over 9,000 programs were sold, 3,000 more than in past years... a number roughly in keeping with the 50 percent increase in attendance cited by officials.

Organizers ran out of press credentials Friday afternoon, and some souvenir stands ran out of products to sell by Saturday. (And Bill's jump went fine, too.)

FMI: Official Show Website