"If you say something really pessimistic about how many people are going to die," explains Ridley, "the media want to believe you. The politicians daren't not believe you."
This bias towards pessimism applies to fear of climate change, too.
Thirty-two years ago, climate "experts" said rising seas would "completely cover" the islands of the Maldives "in the next 30 years." But now, 32 years later, the islands are not only still there, they're doing better than ever. They're even building new airports.
"Climate change is real," says Ridley, "but it's not happening nearly as fast as models predicted."
Models repeatedly overpredict disaster because that's "a very good way of attracting attention to your science and getting rewarded for it," says Ridley.
One more example: For years, "experts" predicted an oil shortage. President Jimmy Carter warned, "The oil and natural gas we rely on for 75% of our energy are simply running out." All the "experts" agreed.
But as the demand for oil grew, oil prices rose. That inspired entrepreneurs to invent new ways of getting more oil and gas out of the same rocks. They succeeded so well that America now has so much oil and gas that we sell some to other countries.
Ridley's new book, "How Innovation Works," shows how innovators prove "experts" wrong all the time.
He points out that the founder of Digital Equipment Corporation once said: "There is no reason anyone would want a computer in their home."
Microsoft's CEO confidently said: "There's no chance the iPhone is going to get significant market share."
New York Times columnist Paul Krugman wrote that because "most people have nothing to say to each other... the Internet's impact on the economy (will be) no greater than the fax machine's."
Of course, not all experts are wrong. Useful experts do exist. I want a trained civil engineer to design any bridge I cross.
But Ridley points out: "There is no such thing as expertise on the future. It's dangerous to rely too much on models (which lead politicians to) lock down society and destroy people's livelihood. Danger lies both ways."