The fundamental problem with banks is what it's always been: they're in the business of banking, and banking, whether plain vanilla or incredibly sophisticated, is inherently risky.

If companies tell us more, insider trading will be worth less.

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.

The Xbox 360 is the best game console ever designed. It's fast and powerful - games look as good on the 360 as on high-end PCs that cost six times as much. It's easy to navigate and has lots of useful secondary features - the ability to play digital video, stream MP3s, and so on.

Solyndra's failure isn't a reason for the government to give up on alternative energy, any more than the failure of Pets.com during the Internet bubble means that venture capital should steer clear of tech projects.

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.

You can't fuel real economic growth with indiscriminate credit. You can only fuel it with well-allocated, long-term investment.