A Field Guide to Lies

rovided by the homeowner. But that can’t be true—it would imply that more than 90 percent of home robberies are solved, because some are certainly solved without home video. What the company more likely means is that 90 percent of solved robberies are from video provided by the homeowner.
Isn’t that the same thing?
No, because the sample pool is different. In the first case, we’re looking at all home robberies committed. In the second case we’re looking only at the ones that were solved, a much smaller number. Here it is visually:
All home robberies in a neighborhood:

Solved home robberies in a neighborhood (using the 30 percent figure obtained earlier):

So does that mean that if I have a video camera there is a 90 percent chance that the police will be able to solve a burglary at my house?
No!
All you know is that if a robbery is solved, there is a 90 percent chance that the police were aided by a home video. If you’re thinking that we have enough information to answer the question you’re really interested in (what is the chance that the police will be able to solve a burglary at my house if I buy a home-security system versus if I don’t), you’re wrong—we need to set up a fourfold table like the ones in Part One, but if you start, you’ll see that we have information on only one of the rows. We know which percentage of solved crimes had h

he evening is safer (in part because people on the road between two and four a.m. are more likely to be drunk or sleep-deprived).
After the Paris attacks of November 13, 2015, CNN reported that at least one of the attackers had entered the European Union as a refugee, against a backdrop of growing anti-refugee sentiment in Europe. Anti-refugee activists had been calling for stricter border control. This is a social and political issue and it is not my intention to take a stand on it, but the numbers can inform the decision making. Closing the borders completely to migrants and refugees might have thwarted the attacks, which took roughly 130 lives. Denying entry to a million migrants coming from war-torn regions such as Syria and Afghanistan would, with great certainty, have cost thousands of them their lives, far more than the 130 who died in the attacks. There are other risks to both courses of action, and other considerations. But to someone who isn’t thinking through the logic of the numbers, a headline like “One of the attackers was a refugee” inflames the emotions around anti-immigrant sentiment, without acknowledging the many lives that immigration policies saved. The lie that terrorists want you to believe is that you are in immediate and great peril.
Misframing is often used by salespeople to persuade you to buy their products. Suppose you get an email from a home-security company with this p

he probability is fallacious. Let’s take a step back. What if you hadn’t run into Justin just as you were standing in front of the Mona Lisa, but as you were in front of the Venus de Milo, in les toilettes, or even as you were walking in the entrance? What if you had run into Justin at your hotel, at a café, or the Eiffel Tower? You would have been just as surprised. For that matter, forget about Justin—if you had run into anyone you knew during that vacation, anywhere in Paris, you’d be just as surprised. And why limit it to your vacation in Paris? It could be on a business trip to Madrid, while changing planes in Cleveland, or at a spa in Tucson. Let’s frame the probability this way: Sometime in your adult life, you’ll run into someone you know where you wouldn’t expect to run into them. Clearly the odds of that happening are quite good. But the brain doesn’t automatically think this way—cognitive science has shown us just how necessary it is for us to train ourselves to avoid squishy thinking.
Framing Risk
A related problem in framing probabilities is the failure to frame risks logically. Even counting the airplane fatalities of the 9/11 attacks in the United States, air travel remained (and continues to remain) the safest transportation mode, followed closely by rail transportation. The chances of dying on a commercial flight or train trip are next to zero. Yet, right after 9/11, many U.S. travelers avoided airplanes and took to the highways instead. Automobile deaths increased dramatically. People followed their emotional intuition rather than a logical response, oblivious to the increased risk. The rate of vehicular accidents did not increase beyon