Since the Protestant majority in Northern Ireland wants to remain a part of Great Britain, and since Ireland itself has shown little interest in reunification, the IRA's prospects for success through political channels have always been limited.

Lower oil prices won't, by themselves, topple the mullahs in Iran. But it's significant that, historically, when oil prices have been low, Iranian reformers have been ascendant and radicals relatively subdued, and vice versa when prices have been high.

When all is said and done, cheap gas is an illusion, because our reliance on gas creates a whole series of costs that aren't factored in to the pump price - among them congestion, pollution, and increased risk of accidents.

Flexible supply chains are great for multinationals and consumers. But they erode already thin profit margins in developing-world factories and foster a pell-mell work environment in which getting the order out the door is the only thing that matters.

Companies often become victims of their own mythologies.

Linux is a complex example of the wisdom of crowds. It's a good example in the sense that it shows you can set people to work in a decentralized way - that is, without anyone really directing their efforts in a particular direction - and still trust that they're going to come up with good answers.

In terms of productivity - that is, how much a worker produces in an hour - there's little difference between the U.S., France, and Germany. But since more people work in America, and since they work so many more hours, Americans create more wealth.