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.

Now, modern economies have a very effective mechanism for deciding if salaries are really too high: it's called the free market. That's how most people's salaries are set, after all, including those of major-league baseball players and European soccer players.

I do think that procrastination evolved in humans for good reasons. If you're trying to stay alive as a human being on the savanna 20,000 years ago, worrying about what's right behind that bush is a lot more important than worrying about what might happen three weeks from now.

The world's central banks and the International Monetary Fund still have vaults full of bullion, even though currencies are no longer backed by gold. Governments hold on to it as a kind of magic symbol, a way of reassuring people that their money is real.

The Internet has become a remarkable fount of economic and social innovation largely because it's been an archetypal level playing field, on which even sites with little or no money behind them - blogs, say, or Wikipedia - can become influential.

The value of a currency is, ultimately, what someone will give you for it - whether in food, fuel, assets, or labor. And that's always and everywhere a subjective decision.

Medical tourism can be considered a kind of import: instead of the product coming to the consumer, as it does with cars or sneakers, the consumer is going to the product.