One of the thicker files here at the office is a well-used folder labeled simply "Happiness."

There's nothing in it from the likes of popular spiritualist and writer Deepak Chopra. Instead it's filled with the work of financial writers, psychologists and economists, all on the topic of money and happiness.

It's a great economic topic. What could be more fundamental than whether more money — getting it, having it, spending it — makes people happier?

The answer, of course, is that more money usually doesn't. It can even make a person feel worse.

"It's only money. Really," begins one article, a 2006 personal finance column by Jonathan Clements of the Wall Street Journal. Another of his ran in 2005 under the headline "Rich, Successful — and Miserable."

Then there's the New York Times article entitled "The Joy of Delusion," a review of the 2006 bestselling book "Stumbling on Happiness." It seems we humans are lousy at predicting what will make us happy. It's one reason why we pursue money or a bigger house. We are somehow completely unaware they won't make us happier.

The last article dropped into the file was published just this month, an essay by the writer Michael Lewis. It was easily the most depressing.

Lewis wasn't sure he bought the argument of a book he was reviewing, on the political influence of billionaires. But he has become convinced that wealth changes a person — and not for the better.

He wrote about one study that showed how drivers of cheap cars overwhelmingly respect pedestrians in a crosswalk and stop, while drivers of expensive cars ignore pedestrians 46 percent of the time.

He cited a survey of 43,000 Americans that found that by a wide margin the rich were more likely to shoplift than the poor.

Another study invited a group of test subjects to a lab and gave them a series of unimportant tasks. The real test was when the subjects were observed leaving the room, passing a big jar of candy with a sign that said the candy was for children.

The richer the person, the researchers found, the more likely he was to reach in and swipe candy from this jar.

Lewis didn't address the happiness of these test subjects, but it's not a leap to conclude that anyone who takes candy from kids may not be all that happy.

It would be easier to dismiss some of these findings if writers like Lewis were cherry picking from obscure studies, but there's been an explosion of research over the past 15 years or so that seems to point to the same conclusions.

When I asked why money and well-being remains of such keen interest to academics, the University of Minnesota's Kathleen Vohs simply responded, "Are you serious?"

It's clear to her the topic could not possibly be a richer mine for any psychologist turned business professor. Vohs called the whole field "fascinating."

Her own work includes what she called the "psychology of money." One of her studies tested whether anyone's behavior changed just by being gently reminded of money, like by playing a game of Monopoly.

In one experiment, the researchers let players keep $4,000 of Monopoly money "for later," while other players got to keep $200 or even no play money. A person holding $4,000 in Monopoly money was then observed to be less likely to help pick up some accidentally spilled pencils.

You have to admit, that's fascinating.

Vohs is a rising star at the Carlson School of Management, and while her own work has not focused on happiness, she said, she sure knows the research findings.

More money can make a big difference at lower incomes, like being able to afford good housing. But after about $20,000 in income the boost in happiness from more money starts to lessen.

"After about $75,000 it completely flatlines," Vohs said. "There's no more happiness you can get from … $200,000, to $500,000, to $1 million and so on."

While that might sound discouraging for those working hard to achieve their financial goals, the good news is there has also been some research that points to a way for people with more money to increase their well-being. No one really has to be the financially successful guy who cheats at Monopoly and rolls a luxury car through occupied pedestrian crosswalks.

The trick is to think far less about you. Spend your money on a meal shared with friends or a trip with the family. Give far more of it to charity. Spend it on people, in other words, and don't just buy more stuff.

It's a good week to stop and think about this, as we are now just a few hours away from a spasm of consumer goods acquisition that starts with Black Friday.

Many bargain hunters shop early for deals this week because they are trying to stretch a tight budget for family members' gifts. The following warning is meant not for them, but maybe for those a little more affluent: Beware of the "Lexus effect."

A more precise term is hedonic adaptation, the psychological phenomenon that explains why having more money doesn't usually make people any happier. The brain quickly adapts to having the nice new things more money can buy, like a Lexus luxury car.

From experience, I can add that knowing all about hedonic adaptation doesn't always lead to good spending choices.

As a consultant some years ago, I chatted all the time with clients about hedonic adaptation, but I also decided one day that a Volkswagen New Beetle was too humble to drive to client meetings. I bought a Volvo convertible, maybe not to make myself happy but just to show off my status in the business world.

That was, of course, a majestic self-delusion.

At first it really was great driving a fancy new convertible, but hedonic adaptation is a powerful thing. That car is now mostly a way to get to work while listening to the news on the radio.

The rusty 1977 Chevrolet Chevelle I drove to my first job after college didn't have a reliable heater, but it did run every day. And the radio still worked.

Looking back, those were some pretty happy times.

lee.schafer@startribune.com • 612-673-4302