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.

You might think of consumption as a fairly passive activity, but buying new products and services is actually pretty risky, at least if you value your time and money.

If private-equity firms are as good at remaking companies as they claim, they don't need tax loopholes to make money.

Businesses that have gone through an episode of hyperinflation become understandably alert to the threat of it: at the first hint of inflation, they're likely to increase prices, since they've learned that if they don't, and inflation hits, their businesses will be wrecked.

Unfortunately, there is something of a flaw in this idealized picture of the way the scientific community discovers truth. And the flaw is that most scientific work never gets noticed. Study after study has shown that most scientific papers are read by almost no one, while a small number of papers are read by many people.

I think people don't understand compound interest because typically no one ever explains it to them and the level of financial literacy in the US is very low.

Markets work best when there's lots of information available and a historical track record to go on; they excel at predicting things like horse races, election outcomes, and box-office results. But they're bad at predicting things like who will be the next Supreme Court nominee, as that depends on the whim of the president.