The reason advertising is governed by fear, after all, is that most agencies rely on just a few clients to bring in the lion's share of their revenues.

In the heart of the Great Depression, millions of American workers did something they'd never done before: they joined a union. Emboldened by the passage of the Wagner Act, which made collective bargaining easier, unions organized industries across the country, remaking the economy.

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.

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.

Making loans and fighting poverty are normally two of the least glamorous pursuits around, but put the two together and you have an economic innovation that has become not just popular but downright chic. The innovation - microfinance - involves making small loans to poor entrepreneurs, usually in developing countries.

In part because individual judgement is not accurate enough or consistent enough, cognitive diversity is essential to good decision making.

I typically don't adopt the ascetic approach. In part, that's because I do use the Net for research even as I'm writing (to check facts, or so on). But I think it's also because I find the possibility of distraction comforting.