Americans spend more than a quarter-trillion dollars on women's luxury goods every year, which may be part of a woman's mating strategy.

Whether purchased by a woman's partner or by herself, a luxury product such as a designer handbag could signal to other women messages about a couple's level of commitment.

Researchers from the University of Minnesota conducted a series of five experiments on hundreds of women of varying ages, married and unmarried, concluding that women use such signals to defend their mating interests from competition, and tend to spend more on luxury goods when they believe they're threatened by competition.

"It might seem irrational that each year Americans spend over $250 billion on women's luxury products with an average woman acquiring three new handbags a year, but conspicuous consumption is actually smart for women who want to protect their relationship," researcher Vladas Griskevicius, told reporters. "When a woman is flaunting designer products, it says to other women 'back off my man.'"

To put such the behavior into perspective, Americans — men and women — spend nearly two-and-a-half times the stated annual military budget of the People's Republic of China, the second-largest spending military competitor to the United States.

Researcher Yajin Wangsaid the ostentatious display of wealth served the same purpose, regardless of whether the woman bought the item for herself.

"We found that a woman who is wearing luxury items and designer brands is perceived to have a more devoted partner and as a result other women are less likely to flirt with him," Wang said. "Regardless of who actually purchased the items, other women inferred that the man had something to do with it and is thus more devoted to her."

The conspicuous conception of luxury goods, presumably unconnected with childrearing and other practical concerns, send an ancient signal to competitors in the human ape world.

"The feeling that a relationship is being threatened by another woman automatically triggers women to want to flash Gucci, Chanel, and Fendi to other women," Wang said. "A designer handbag or a pair of expensive shoes seems to work like a shield, where wielding a Fendi handbag successfully fends off romantic rivals."

Moreover, women spend nearly one-third more on luxury goods when they feel threatened by romantic competition, the researchers found.

The research highlights a key difference between men and women using material consumption as a mating ploy. Previous study by Griskevicius has shown that men often consume as a way to attract mates interested in his material resources — taking an offensive rather than defensive posture.

Interestingly, Wang said they were surprised that feelings of jealousy would evince desire for such luxury goods in single women, with nothing to defend.

"Many single women obviously want designer products, but instead of these products saying back off my current man, the single woman is saying back off my future man," Wang said. "Conspicuous consumption for women has a lot to do with subtle status within the female group."

Source: Griskevicius, Vladas, Wang, Yajin. Conspicuous Consumption, Relationships, and Rivals: Women's Luxury Products as Signals to Other Women. Journal of Consumer Research. 2013.