Bubble Spotting

NEW HAVEN – People frequently ask me, as someone who has written on market speculation, where the next big speculative bubble is likely to be. Will it be in housing again? Will it be in the stock market?

I don’t know, though I have some hunches. It is impossible for anyone to predict bubbles accurately. In my view, bubbles are social epidemics, fostered by a sort of interpersonal contagion. A bubble forms when the contagion rate goes up for ideas that support a bubble. But contagion rates depend on patterns of thinking, which are difficult to judge.