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.

Tough times have always lent themselves to nativist sentiments and closed-door policies. But in the case of highly skilled immigrants these policies are a recipe for stagnation.

I tend to delay writing by doing more research - it's really the act of writing the piece that I have the hardest time with.

In effect, dividing your attention means that neither (or none) of the things you're working on is really getting the full effect of your intelligence, and that it in the end takes you longer than it would if you did one thing at a time.

There does seem to be some evidence that as people get older, they procrastinate less, perhaps because they feel the pressure of time more.

The history of the Internet is, in part, a series of opportunities missed: the major record labels let Apple take over the digital-music business; Blockbuster refused to buy Netflix for a mere fifty million dollars; Excite turned down the chance to acquire Google for less than a million dollars.

The smartest groups, then, are made up of people with diverse perspectives who are able to stay independent of each other.