Market timing, by the way, is a tag some buy-and-hold investors use to put down anything that involves using your brain. These are the same people who like to watch the locomotive coming and get run down in the name of discipline.

I find the parallels between how some investors refuse to recognise the trends and our reaction to some of our environmental challenges very powerful. There is an unwillingness to process unpleasant data.

If stocks are attractive and you don't buy, you don't just look like an idiot, you are an idiot.

Profit margins are probably the most mean-reverting series in finance, and if profit margins do not mean-revert, then something has gone badly wrong with capitalism. If high profits do not attract competition, there is something wrong with the system and it is not functioning properly.

Americans are just about the worst at dealing with long-term problems, down there with Uzbekistan, but they respond to a market signal better than almost anyone. They roll the dice bigger and quicker than most.

The investment business has taught me – increasingly as the years have passed – that people, especially investors (and, I believe, Americans), prefer good news and wishful thinking to bad news; and that there are always vested interests to offer facile, optimistic alternatives to the bad news.

There is no single theory that is used in economics that considers the finite nature of resources. It's shocking.