With all the bad economic news these days, it's hard to believe every company isn't struggling just to survive. But for all the damage they do, recessions often help the best businesses widen their lead over the competition. "The true sign of greatness is a company's ability to emerge from difficult times stronger than it was going in," says Jim Collins, author of the just-published Good to Great: Why Some Companies Make the Leap...And Others Don't.
Some market leaders, like Wal-Mart and Dell, have such enormous scale and low cost structures that they can use aggressive pricing to bleed their...