THE global signs of a recovery in economic confidence seem puzzling.
It is a large and diverse world, after all, so why should confidence have rebounded so quickly in so many places? Government stimulus and bailout packages have generally not been big enough to have such a profound effect.
What happened? Economic analysts often turn to indicators like employment, housing starts or retail sales as causes of a recovery, when in fact they are merely symptoms. For a fuller explanation, look beyond the traditional economic links and think of the world economy as driven by social epidemics, contagion of ideas and huge feedback loops that gradually change world views. These social epidemics can travel as swiftly as swine flu: both spread from person to person and can reach every corner of the world in short order.
As George Akerlof and I argue in our book, “Animal Spirits,” the business cycle is tied to feedback loops involving speculative price movements and other economic activity — and to the talk that these movements incite. A downward movement in stock prices, for example, generates chatter and media response, and reminds people of longstanding pessimistic stories and theories. These stories, newly prominent in their minds, incline them toward gloomy intuitive assessments. As a result, the downward spiral can continue: declining prices cause the stories to spread, causing still more price declines and further reinforcement of the stories.
At some point, of course, the process must end, as when the market falls so low that it becomes enticing, or when new stories emerge. Similarly, an upward movement in stock prices generates its own upward feedback.
At first, the feedback explanation may sound too simple, and may suggest that the stock market and its turning points are easy to predict. But because day-to-day noise shrouds these changes, and because the stories change in their retelling and as new evidence emerges, the process is actually very complex.
And even when feedback mechanisms are straightforward, they can produce very strange outcomes, not predictable very far into the future, as the modern mathematics of chaos theory can attest.