“When I look back at my life,” one of these high rollers explained, “I like remembering myself happy. So if it makes me happy, it’s worth it.”

Image Credit... Viktor Koen

Aesop told a fable of two types of people: the virtuous Ant who saves for the winter and the improvident Grasshopper who’s punished with starvation. But even the most conscientious Ants sometimes recognize the need to lighten up  and, with typical Ant discipline, will find ways to “precommit to indulgence,” as Dr. Kivetz discovered in a lottery experiment he conducted with Itamar Simonson of Stanford University.

The experimental participants, who were all women, were given a ticket for a lottery drawing to be held three months later, and asked to choose in advance which prize they’d prefer if they won: $85 in cash, or a voucher for an $80 massage or facial at a spa. They were reminded that they could simply use the $85 in cash to buy the spa treatment (and have $5 left over), but even so, more than a third of the women chose the voucher for the spa.

Similar results turned up when the researchers asked men and women to pick other kind of prizes or to redeem points earned in frequent-buyer programs. When choosing between cash and “hedonic luxuries” like bottles of wine, dinners or vacations, a substantial minority chose the luxuries even though the cash was a better deal.

“If I took the cash,” one person explained, “it would end up going into the rent.” Another wrote of her decision: “That way I’d have to pamper myself and not spend the $ on something like groceries.”

Other experiments showed that people will work harder for luxuries than for more practical prizes  and the more effort that’s required, the more they feel entitled to a self-indulgent reward. That’s a motivation strategy for managers and marketers to keep in mind, Dr. Kivetz said.

During the current recession, hyperopic Ants are presumably having a harder time than ever parting with their own cash, no matter how often President Obama and his economists urge them to do some stimulative shopping. But would these Ants  and the economy  be better off if they relaxed a little? (You can provide an answer at TierneyLab, nytimes.com/tierneylab. ) I asked Dr. Kivetz for his advice to shoppers.