WHEN Nobel Prize-winning psychologist Daniel Kahneman was a young man, he led a committee to write a new part of the curriculum for Israeli high schools. The committee worked for a year, and Dr Kahneman asked his colleagues how long they thought the rest of the project would take. Their estimates were around two years.
By David Brooks
Dr Kahneman then asked the most experienced among them how long such work took other curriculum committees. The gentleman pointed out that roughly 40 per cent of the committees never finished their work at all.
But what about those that did finish? The gentleman reported that he had never seen a committee finish in less than seven years and never in more than 10.
This was bad news. They might fail to finish a task that they thought would be done in three years. At best, the project might consume eight or nine years. Yet this information didn't affect those on the team at all. They carried on, assuming that though others might fail or dally, surely they wouldn't.
As it turned out, their project took eight years to finish. By the time it was done, the Education Ministry had lost interest, and the curriculum was never used.
In his forthcoming book, Thinking, Fast And Slow, Dr Kahneman calls this the planning fallacy. Most people overrate their own abilities and exaggerate their capacity to shape the future. That's fine. Optimistic people rise in this world. The problem comes when these optimists don't look at themselves objectively from the outside.
The planning fallacy is failing to think realistically about where you fit in the distribution of people like you. As Dr Kahneman puts it: 'People who have information about an individual case rarely feel the need to know the statistics of the class to which the case belongs.'
Over the past three years, the United States has been committing the planning fallacy on stilts. The world economy has been slammed by a financial crisis. Countries that are afflicted with these crises typically experience several years of high unemployment. They go deep into debt to end the stagnation, but the turnaround takes a while.
This historical pattern has been universally acknowledged and universally ignored. Instead, leaders in both parties have clung to the analogy that the economy is like a sick patient who can be healed by the right treatment.
The Democrats, besotted by the myth that the New Deal ended the Great Depression, have consistently overestimated their ability to turn the economy around. They regard the Greek crack-up as a freakish, unlucky break, even though this sort of thing is a typical feature of a financial crisis.
Republicans, who should know better, also have an inflated sense of the power of government. In the presidential debates, Mr Rick Perry, Mr Mitt Romney and Mr Jon Huntsman argue about which one oversaw the most job creation during his term as governor, as if governors have an immediate and definable impact on employers' hiring decisions.
The reality, of course, is that the economy is not a patient. It is a zillion, zillion interactions. Government is not a doctor. Most of the time, it is a clashing collective enterprise that is occasionally able to produce marginal change, for good and for ill.
Democrats should be learning about the limits of social policy. As in the war on poverty, as in the effort to transform American schools, as in the effort to create prosperity in the developing world, it is really hard to turn around complex systems.
Republicans should be reflecting on the fact that if a Republican president were in office right now, and even if he or she did sensible things, the economy would still be in the dumps. It would be Republicans losing 'safe' congressional seats in special elections.
The key to wisdom in these circumstances is to make the distinction between discrete good and systemic good. When you are in the grip of a big, complex mess, you have the power to do discrete good but probably not systemic good.
When you are the president in a financial crisis, you have the power to pave roads and hire teachers. That will reduce the suffering of real people who would otherwise be jobless. You have the power to streamline regulations and reduce tax burdens. That will induce a bit more hiring and activity. These are real contributions.
But you don't have the power to transform the whole situation. Your discrete goods might contribute to an overall turnaround, but that turnaround will be beyond your comprehension and control.
Over the past decades, Americans have developed an absurd view of the power of government. Many voters seem to think that government has the power to protect them from the consequences of their sins. Then they get angry and cynical when it turns out that it can't.
NEW YORK TIMES