Downsizing itself is an inevitable part of any creatively destructive economy.

Steve Jobs was rare: a C.E.O. who actually had a huge impact on his company's fortunes. Contrary to corporate mythology, most C.E.O.s could be easily replaced, if not by your average Joe, then by your average executive vice-president. But Jobs genuinely earned the label of superstar.

The smartest groups, then, are made up of people with diverse perspectives who are able to stay independent of each other. Independence doesn't imply rationality or impartiality, though. You can be biased and irrational, but as long as you're independent, you won't make the group any dumber.

Sometimes you have to destroy your business in order to save it.

Disasters redistribute money from taxpayers to construction workers, from insurance companies to homeowners, and even from those who once lived in the destroyed city to those who replace them. It's remarkable that this redistribution can happen so smoothly and quickly, with devastated regions reinventing themselves in a matter of months.

The fact that cognitive diversity matters does not mean that if you assemble a group of diverse but thoroughly uninformed people, their collective wisdom will be smarter than an expert's. But if you can assemble a diverse group of people who possess varying degrees of knowledge and insight, you're better off entrusting it with major decisions rather than leaving them in the hands of one or two people, no matter how smart those people are.

Most of the work on multitasking suggests that it generally makes you less efficient, not more.