Taking a rational look at the risk of threats

THE terrorist attacks in Paris last week that killed 130 people and injured hundreds more instilled fear in millions of people who weren't anywhere near the attacks. That, of course, is the point of terrorism.

The sheer randomness of the attacks will persuade some people who may be at higher risk to dismiss any chance that they could find themselves in a similar situation, while others with no need for concern will worry excessively.

"We as human beings don't perceive risk rationally," said Martin Hartley, chief operating officer of Pure Insurance, a company aimed at wealthy clients. The Paris terrorism, he said, "makes the risk seem far worse by its magnitude not by its probability. That's the challenge of risk." Which risks are worth guarding against and which ones aren't? For a fee, various consultants are offering to answer that question.