The problem is that groups are only smart when the people in them are as independent as possible. This is the paradox of the wisdom of crowds.

Auto repair, piloting, skiing, perhaps even management: these are skills that yield to application, hard work, and native talent. But forecasting an uncertain future and deciding the best course of action in the face of that future are much less likely to do so. And much of what we've seen so far suggests that a large group of diverse individuals will come up with better and more robust forecasts and make more intelligent decisions than even the most skilled "decision maker."

Real politics is messy and morally ambiguous and doesn't make for a compelling thriller.

Companies have long gathered data to break down their customer base into specific segments. Now political parties have become adept at micro-targeting, too, using data on shopping habits, leisure activities, voting histories, charity donations, and so on, in order to pinpoint likely supporters and the type of appeal most likely to win them over.

Bubbles and crashes are textbook examples of collective decision making gone wrong. In a bubble, all of the conditions that make groups intelligent - independence, diversity, private judgement-disappear.

There are certainly valid reasons for taking a company private, and it's also possible that C.E.O.s perform better when monitored by a small number of owners in a private company rather than by the dispersed and often uninterested shareholders of a public corporation.

Sometimes even a smart crowd will make a mistake.