Do you believe that women are scarce? Then, it is most likely that you will spend more on them, researchers say.

However, a dearth of men doesn't make women spendthrifts, but believing men are plentiful does trigger women to believe men should be spending more on them, found the researchers at the University of Minnesota.

The research was done in a laboratory setting, but there is some real-world evidence that cities with higher ratios of men also have higher levels of debt, the researchers said.

Similarly, the wild animal kingdom is rife with such competitive behaviour, said Vladas Griskevicius, a professor of marketing at the University of Minnesota who led the study.

"What we see in other animals is that when females are scarce, males become more competitive. They compete more for access to mates," Griskevicius was quoted as saying by LiveScience.

"How do humans compete for access to mates? What you find across cultures is that men often do it through money, through status and through products."

For the study, published in the Journal of Personality and Social Psychology, the participants read news reports that described their local populations being either male- or female-skewed.

Next, they were asked to report how much money they would save each month from a given paycheck, as well as how much credit card debt they would take on.

When led to believe women were scare, men decreased their savings rate by 42 per cent and indicated they were willing to borrow 84 per cent more each month, the researchers said.

In another study, the participants looked at a series of pictures that either had more men, more women, or equal gender ratios. Then the participants chose between receiving a small amount of money immediately versus a larger amount in a month.

When women were scarce in the photos, men were more likely to take USD 20 right away rather than USD 30 later.

"There are more men than women in our environment and it automatically changes our desires our behaviours and our entire psychology," Griskevicius said.

However, women weren't affected like men. When they read that their area was populated with more men than women, they expected men to spend more on courting-related expenses such as dinner dates and engagement rings, the researchers found.

"When there's a scarcity of women, women felt men should go out of their way to court them," Griskevicius said.

An analysis of 120 US cities provided some tantalising real-world backup for the results found in the lab.

Communities with a population skewed toward men had higher debt levels and greater ownership of credit cards, the researchers found.

For example, in Columbus, where there are 1.18 single men for every single woman, the average consumer debt was USD 3,479 higher than in Macon, less than 100 miles away but with 0.78 single men for every woman, they said.