I recently made an economic exchange that wasn’t entirely rational. I paid people at Tufts University’s small-animal hospital $4,000 as a deposit on an estimated $6,000 medical bill. This was for treating a cat that, six months ago, nobody wanted. Nobody except me, and back then I wouldn’t have been crushed if someone else had taken him and I had to choose a different cat.

But nobody did. The shelter charged me half price on the nominal adoption fee because the staff was so happy someone was finally taking away this lanky, brown-and-black 11-year-old named Pooh Bear.

I may have been the only taker for Pooh Bear, but there in the hospital waiting room I could see I wasn’t alone in being attached to a well-worn, somewhat decrepit animal. Others, one by one, were called to the front desk where they agreed to pay hundreds or thousands for a chance at saving a sick dog or cat — or in one case, a parakeet.

It got me thinking about some of the science of decision-making, particularly a phenomenon called loss aversion. I felt susceptible to this, considering how far I was willing to go not to lose this cat.

Psychologists Daniel Kahneman and Amos Tversky discovered loss aversion in studying how people make economic decisions. It’s nicely explained in Kahneman’s book “Thinking, Fast and Slow.” The idea is not just that people don’t like losing. That’s pretty obvious. Loss aversion exists because the fear of losing is greater than the hope of making an equivalent gain.

And people will gamble to avoid a loss. As Kahneman illustrates, we usually prefer getting a sure $900 than a 90 percent chance of getting $1,000, but we’d rather take a 90 percent chance of losing $1,000 than a sure loss of $900.

A closely related tendency is called the endowment effect. In bartering experiments, most subjects are unwilling to sell small items — a mug or a pen — for anything close to what they originally paid. People get attached to things.

I was very attached to this cat. When I first saw him, Pooh Bear had lived in a Providence animal shelter for six months — longer than any other cat there. And this was his second stay there. He’d been rejected by at least two previous owners. I took him knowing he was a senior citizen and had shown signs of heart disease. I liked him and thought he deserved a break.

He was so big and long-legged that I had to bring him home in a dog crate, and soon bought him a dog bed. He was not as advertised. The people at the shelter said he was cuddly. He refused to sit on laps, or even on the same side of the couch with me. He wasn’t all that fond of being petted.

But as I got to know him, he was basically friendly, and he was funny. He had expressive yellow-green eyes and sometimes used them to shoot me a look of such pure contempt that he resembled a different story book character — not Winnie the Pooh but the Grinch. Instead of meowing, he strutted around saying “mrap mrap mrap” with a wisecracking tone.

And then one frigid January night he got sick — vomiting repeatedly, trembling, hiding under the couch. Because I’d been warned he’s at high risk for heart failure, I blew $600 and a full night of sleep on an emergency room visit. They ruled out heart failure.

But the next day he’d barely moved from the same spot. He was crying out in distress. It was Saturday, and the regular vet was closed — hence the trip to the Foster Hospital for Small Animals, which is part of the Tufts University Veterinary School, nearly an hour’s drive from home. They wanted to admit him, with an estimated cost of $3,000. I gave them my credit card.

By the next day the stakes were higher. The estimate had risen to $6,000, because the tests revealed something blocking a bile duct, and the doctors recommended surgery. They told me he had a 40 percent chance of dying on the operating table. But what was the alternative? He was suffering, and this was a potential solution.

I started writing about loss aversion a year ago because a researcher at the University of Illinois named David Gal emailed me to say that he’d written a critique of loss aversion. He’d tried to replicate some of the famous experiments and failed, and came to doubt the phenomenon existed.

While it’s true that some psychological phenomena have recently been called into question when people failed to replicate experiments (the so-called replication crisis), loss aversion was based on several different kinds of experiments. Even if some turned out to be in error, that wouldn’t necessarily invalidate the idea.

My impending loss of Pooh Bear sent me back to bookmarked chapters of Kahneman’s book. I was struck by a short passage he wrote in warning: “All bets are off if the possible loss is potentially ruinous, or if our lifestyle is threatened.” He went on to write that the loss aversion coefficient might be infinite in some cases — that is, there are risks people won’t take, no matter what the potential gain.

This deserves more attention. Many of our most momentous decisions fall into the all-bets-are-off category. In the book, Kahneman describes loss aversion as an extension of our survival instinct. But sometimes in health care we’re dealing with actual survival. Then we are no longer being predictably irrational, but acting on our perfectly reasonable fear of dying or of losing those we love. I know, intellectually, that when Pooh Bear dies, I can get another, cuddlier cat — or a small dog. I already had the dog crate and the bed. But I wanted this cat — my funny, wisecracking cat — and I was willing to pay dearly not to lose him. That’s why I handed over my credit card.

It turned out the hospital couldn’t do surgery because the veterinarians deemed Pooh’s heart disease too advanced for him to survive general anesthesia. A second ultrasound showed the blockage had broken up a bit, and he recovered over the next three days. The price tag ultimately was a bit over $2,000 — but remember that in the midst of the crisis, I had been willing to pay at least $6,000.

I took Pooh home, and I considered myself lucky. Loss averted.

Faye Flam is a Bloomberg Opinion columnist. She has written for The Economist, The New York Times, The Washington Post, Psychology Today, Science and other publications. She has a degree in geophysics from the California Institute of Technology.

In a time of both misinformation and too much information, quality journalism is more crucial than ever.
By subscribing, you can help us get the story right.