From his Q & A at the publisher's website:
How did you discover the wisdom of crowds?--Marshal Zeringue
The idea really came out of my writing on how markets work. Markets are made up of diverse people with different levels of information and intelligence, and yet when you put all those people together and they start buying and selling, they come up with generally intelligent decisions. Sometimes, though, they come up with remarkably stupid decisions—as they did during the stock-market bubble in the late 1990s. I was interested in what explained the successes and the failures of markets, and as I got further into it I realized that it wasn't just markets that were smart. In fact, crowds of all sorts were often remarkably wise.
Could you define "the crowd?"
A "crowd," in the sense that I use the word in the book, is really any group of people who can act collectively to make decisions and solve problems. So, on the one hand, big organizations—like a company or a government agency—count as crowds. And so do small groups, like a team of scientists working on a problem. But just as interested—maybe even more interested—in groups that aren't really aware themselves as groups, like bettors on a horse race or investors in the stock market. They make up crowds, too, because they're collectively producing a solution to a complicated problem: the bets of people betting on a horse race determine what the odds on the race will be, and the choices of investors determine stock prices.
Under what circumstances is the crowd smarter?
There are four key qualities that make a crowd smart. It needs to be diverse, so that people are bringing different pieces of information to the table. It needs to be decentralized, so that no one at the top is dictating the crowd's answer. It needs a way of summarizing people's opinions into one collective verdict. And...[read on]