Legend has it that there are just as many rats as people in the city — eight million.
But a researcher says he's debunked the myth, and that an “extremely generous estimate of the city’s rat population" would put the number at, well, only two million!
The new analysis by Jonathan Auerbach, a PhD student of statistics at Columbia University, was published in the journal Significance. As the press release states:
“The analysis classified rat sightings by city lot, of which there are roughly 842,000 in New York City. The researchers estimated 40,500 rat-inhabited lots in the city. By liberally assuming that 40 to 50 rats belong to a typical colony and that one full colony occupies each rat-inhabited lot, the researchers concluded that 2 million would be an extremely generous estimate of the city's rat population.”
As for that eight million number? Auerbach writes in the analysis that each lot would have to support "its own colony of around 180 rats for a total popluation of eight million to be plausible." He writes that the one-rat-per-person theory was first floated in the early 1900s based on estimates in England that were applied to the city.
Of course, two million is still a lot of rats scurrying in subway tunnels, burrowing into holes in parks and darting across sidewalks.