#### Who is behind that forecast?

- In The Curious Science of Counting a Crowd, Rob Goodier says “when turnout implies clout, politicians and event organizers have plenty of motivation to exaggerate.”
- Charles Seife, author of “Proofiness,” said New York City claims a huge number to communicate itself as “the center of the universe.”
- Steve Doig, a data journalism professor, says “The size of my crowd is a measure of how wonderful I am.”
- Sabrina Stierkalb of Everyday Einstein says “the biggest obstacle to getting an accurate estimate of crowd size appears to be who is doing the counting.”

#### The Sky is Falling.

In that article from April 16, 2018, I wrote about how one person turned a 311 person fact into a 60,000 person fiction *because it is in most people’s interests to exaggerate*. So much so that people typically claim crowd sizes of 10 to 100 times the actual numbers. Seife says we “are routinely bamboozled by phony data, bogus statistics, and bad math,” and *we have the right and the obligation to ask questions about where big numbers come from*.

#### Simple Math.

Scientists measure crowds by *density* per square meter or square yard. Draw a square 3 feet on a side and see how many of your friends or colleagues can stand inside it. They must be fully inside, and not spilling over the edges because your square will be surrounded by other squares. Herbert Jacobs, a Berkeley professor and the father of *grid-based crowd measurement*, said 1 person per square meter is a loose crowd, 2 is a solid crowd, and 4 is a very dense crowd, or what he calls *“mosh pit density.”*

#### Scientists say Times Square is approximately 17,000 square yards.

That’s about two city blocks in Manhattan. Let’s round that up to 20,000 square yards to keep the math simple. At mosh pit density, the total number that can fit in that area is about 80,000 people. Organizers will rightfully claim there will be people on perches and hanging out of windows, so let’s double it to 160,000. This already-inflated and rounded-up number renders the claim of 2 million **outrageous and unbelievable**. The only way to get 2 million people into Times Square is to get ten layers of people standing on each other’s shoulders.

*You will be the center of attention tonight when you tell your friends what you know about estimating the size of crowds.*