Trying to Herd a Cat Stat (Wall Street Journal)

(No matter the number, they should not be outdoors!)

Can a single female cat and her offspring really produce 420,000 cats over just seven years?
Hundreds of media reports have repeated that startling stat -- in the past month alone, the number has appeared in the Dallas Morning News, the Tulsa World and the Times-Herald of Vallejo, Calif. It also turns up on many Web sites for animal advocacy groups who want to see more aggressive spaying and neutering, and urge people to adopt more cats.
I did some digging, and discovered that no one wanted to claim ownership of this stray stat.
The number is often attributed to the Humane Society of the United States, which lists it on a page of stats on the Humane Society Web site. But the group told me it's not the source of the figure. "That number is flawed," John Snyder, vice president of companion animals for the Humane Society, told me. "We no longer believe it." He added, "I have no idea where that number came from."
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Does the 420,000 estimate sound reasonable to you? Should advocates use exaggerated numbers to advance a worthy cause? If you're a pet owner, do you have your pets spayed or neutered? Join a discussion with Carl Bialik.
Another prominent group, the American Society for the Prevention of Cruelty to Animals (which is unaffiliated with the Humane Society), has used the number in press releases and in a cat rescue program on the group's Web site. Local SPCAs in Ontario, San Francisco and Bakersfield, Calif., also use the number.
An ASPCA spokeswoman told me the group got the stat from the Humane Society.