For most of us, airports are the only places where life has really changed since 9/11. The terminal has become a vast theater of the absurd where aspiring passengers line up halfway back to town. The shoes of little old ladies are gravely removed and inspected. Men in suits take their cell phones out of the bag and put their laptop computers into the bag-no, wait, cell phones in and computers out. Random passengers stand spread-eagled while strangers say to them softly, "Now I'm going to run my hands around your waist. Is that all right?" Somewhere unseen, a food-service worker is assembling plastic knives but metal forks in meals headed for first class. And all the while the public-address system hectors us to "report any suspicious activity."

Many people, understandably skeptical about these quasi-religious rituals, have stopped flying instead. Others are thinking about moving out of New York and other big cities, and some have done so. These are responses more in keeping with the scale and drama of the episode that provoked them, but they may not make any more sense. David G. Myers of Hope College in Holland, Mich., calculated that terrorists would have to hijack 50 planes a year and kill everyone aboard before flying would be more dangerous than driving an equal distance. The steps we have taken to protect ourselves from terrorism (not counting the military effort to stop it at the source) seem either farcically trivial or farcically excessive. Is there a rational middle ground?

Dealing rationally with the risks of terrorism is hard for several reasons. First, human beings are bad at assessing small risks of large catastrophes. And Americans are especially bad at this because we are Americans, and catastrophes are not supposed to happen to us. Our legal culture, our political culture and our media culture all push us toward excessive caution by guaranteeing that any large disaster will produce an orgy of hindsight. Lawyers will sue, politicians will hold hearings, newspapers and newsmagazines will publish overexcited revelations about secret memos that could be interpreted as having warned of this if held up to the light at a certain angle. Second, the actual risk of being a terror victim is not merely small-it is unknown and unknowable.

Economists make a distinction between "risk" and "uncertainty." Risk refers to hard mathematical odds. Uncertainty refers to situations in which the odds are anybody's guess Third, even knowing what is theoretically knowable is impossible for most of us. Just attempting to list the fields of knowledge where expertise would be required strains my own ignorance: aeronautical engineering, Middle Eastern politics, nuclear physics, um, microbiology? Clinical psychology? Without a clue about most of these subjects, how can citizens think rationally about them?

Walter Lippmann, in his famous 1922 book, Public Opinion, said the solution was to turn over most public-policy questions to boards of experts. Fourth, it's hard to be rational about the irrational. Who can guess intelligently what Osama bin Laden might want to try next? How can you discourage a suicide bomber who is looking forward to being dead after killing you? Irrationality holds a treasured place in game theory, the branch of economics dedicated to strategic questions of this sort.

Game theory's great insight is that irrationality can be an asset. If you can convince the world that you're nuts-and the surest way to do that is to be nuts-your behavior becomes impossible to predict or control. You become, in a way, invulnerable. What all this adds up to is a strong suspicion that we are not doing too little about terrorism: we are probably doing too much. Our initial instincts are overly risk averse; the danger probably looms larger than it should. A crazed terrorist's next move is going to be a surprise: the burdens we impose on ourselves out of hindsight from the last episode are unlikely to be the ones hindsight will recommend after the next one.

We can be skeptical about the warnings of terrorism "experts." They have a psychological or even financial interest in erring on the side of panic. Before we avoid skyscrapers in case they are hit by hijacked airplanes, we should consider other risks and what we are doing to avoid them. About 4,000 people die by accidental drowning every year. That's more than died on 9/11. Rationality cannot tell us precisely what it's worth to avoid an unknowable risk. But rationality can compare risks and gently suggest that you should not worry about one risk if you are happily oblivious to another.

In short, a more rational approach to protecting ourselves from terrorism may not be doing more about it, or doing something different, but actually doing less. We need the courage and good sense to bury our heads in the sand a bit.

By Michael L. Rothschild

The odds of dying in an automobile accident each year are about one in 7,000, yet we continue to drive. The odds of dying from heart disease in any given year are one in 400 and of dying from cancer one in 600, yet many of us fail to exercise or maintain a healthy diet. We have learned to live with these common threats to our health. Yet we have been afraid to return to the malls and the skies.

What are the odds of dying on our next flight or next trip to a shopping mall? There are more than 40,000 malls in this country, and each is open about 75 hours per week. If a person shopped for two hours each week and terrorists were able to destroy one mall per week, the odds of being at the wrong place at the wrong time would be approximately 1.5 million to 1. If terrorists destroyed one mall each month, the odds would climb to one in 6 million. This assumes the total destruction of the entire mall; if that unlikely event didn't occur, the odds would become even more favorable.

In another hypothetical but horrible scenario, let us assume that each week one commercial aircraft were hijacked and crashed. What are the odds that a person who goes on one trip per month would be in that plane? There are currently about 18,000 commercial flights a day, and if that person's trip has four flights associated with it, the odds against that person's being on a crashed plane are about 135,000 to 1. If there were only one hijacked plane per month, the odds would be about 540,000 to 1.

Stories in the news media have begun to consider the virtue of a public relations campaign in Muslim nations to bring our side of the war to the populations of these countries. While this can be an important strategy, I would like to suggest that we need an information campaign in this country as well, because a key element of life after Sept. 11 has not been well presented to the public: Our leaders and media have not done a good job of discussing the risks that citizens need to consider when making choices in their daily lives. We are presented with a continuous stream of stories telling us about the most recent horrible incident and the possibilities of future terrors. Frequent repetition of these stories may lead people to overestimate the likelihood of future dire events.

While we need to be made aware of potential dangers, we also need to understand the true probabilities of these risks. In the above examples, the scenarios were pretty extreme; the odds of any one of us being directly affected by a lesser event would be even more remote. People tend to underestimate the probability of a common event's occurring but overestimate the probability of a rare event.

These findings may be due in part to the frequency with which we are exposed to news stories about the remote versus the common event. Anthrax, which has so far claimed five lives out of a population of 275 million, is a continuous story, while smoking-related illnesses, which claim about 400,000 lives per year, are not a news story at all. Anthrax is a big story and is worthy of media attention, but people may be overreacting in changing their personal behavior because of this remote event. Perhaps they overestimate the potential probabilities that an anthrax-related incident could happen to them because of the frequency with which they see anthrax-related news stories.

In Madison, Wis., it was reported that in some neighborhoods parents didn't allow their children to go trick-or-treating at Halloween because of the heightened risks of terrorism. What are the odds that any single child would be affected by terrorists on that one night? We need to separate the probability that an event may occur in our country and the probability that it will occur to us as individuals. In making an informed decision about my own behavior, I need to know the probability that I will be personally affected by a terrorist act, not what the probability is that such an act may occur at some place and some time.

We each have many opportunities to take various actions each day. Each opportunity has multiple choices and multiple outcomes. Each of us must independently make our own decisions, but we are being given incomplete information on which to base these decisions. As a result we may have been unnecessarily cautious. The economic cost to our nation in lost expenditures, resulting in lost jobs and lost businesses, has been enormous. While the impact of any potential event on any one of us is slight, the impact of the sum of our individual behaviors is great.

There is a key question that we need to consider: What are the odds that I, myself, will be at the exact wrong place at the exact wrong time? While any terrorist event is horrible, if I act with respect to my own real risk and the probability that I, personally, will be affected, then I can return to a more normal life.

If I act as if each terrorist act will be directed specifically at me, then I will hide, and collectively we will all hide.

The writer is an emeritus professor at the University of Wisconsin's business school. © 2001 The Washington Post Company

Anxiety and Stress Disorders Institute of Maryland:
Treating anxiety disorders and stress-related disorders in Towson, Maryland, since 1978.