A minority of people — 10 to 30 percent, depending on the situation — continues to overestimate the risk and behave more hysterically, or overreact. These are the people who are causing much of the rush on supplies like toilet paper and emptying the shelves. This is a problem, of course, because it can prompt the same kind of behavior in others. But the important point is that this is a minority. Most people have the opposite problem.

So the overall effect, over time, is more complacency than panic?

Yes. I returned to Israel from sabbatical in the U.S. during the second Intifada, in 2002. Officials were saying that it was extremely dangerous to be in coffee shops, and my wife and I bought a fancy coffee maker and stayed inside. For a few days, the coffee shops were nearly empty, and the tourists certainly stopped coming. But the locals came out, and soon the places were full again. We knew it was still dangerous; we just began to underweight the risk, with time.

The same thing is likely to happen with the coronavirus. People will self-isolate for a time and then, when nothing happens, they don’t get sick, they’ll begin to go out again — taking more risks than they had planned to.