Friday the 13th, the number eight and other superstitions not only signal luck or lack thereof but also affect consumer decisions, a study suggests.

Researchers Thomas Kramer and Lauren Block, from New York's Baruch College, found that consumers are more likely to be disappointed if a product boasting a lucky characteristic, like a colour, fails. A second experiment found that even thinking about a negative superstition can make consumers more cautious.

In a study to be published in April's Journal of Consumer Research, the pair surveyed 48 students from a Taiwanese university on superstition and consumer preferences.

They found that Taiwanese consumers expected to be more disappointed if a rice cooker that was red, a lucky colour in Chinese culture, burned the rice as opposed to one in the neutral colour green.

"Positive superstitious beliefs concerning colours and numbers affect product satisfaction judgment, showing that product failure results in lower satisfaction for products for which positive superstitious associations with an attribute exist," the researchers wrote. "Additionally, we showed that product failure leads to higher satisfaction for products with associated negative superstitions."

When the consumers were made conscious of superstitions beforehand, through a questionnaire, researchers found they were equally disappointed with the coloured rice cookers.


A previous study found that Taiwanese consumers were more likely to purchase a radio priced at lucky number $888 than one at $777, despite the 15-per-cent increase in price.

Superstition is alive and well in the United States too, Kramer and Block say. Studying 95 American college students, the researchers found that having participants think about Friday the 13ths made them significantly more risk averse.

Some students were asked to think about Friday the 13th while others were told to think about Tuesday the 19th. Then, in what was called an unrelated study, they were asked to bet for either a guaranteed $18 or a 20-per-cent chance to win $240. Those who had thought about unlucky Friday the 13th chose the safe option nearly half the time, as opposed to only 35 per cent of those who had thought about the neutral day.

"In particular, we show that superstitious beliefs have a robust influence on product satisfaction and decision-making under risk," the researchers wrote. "However, these effects are only observed when superstitious beliefs are allowed to work nonconsciously."

Their study says between $800 and $900 million is lost in business every Friday the 13th. Additionally, they said an estimated nine per cent of Americans are paraskevidekatriaphobics, meaning afflicted with a fear of Friday the 13th.

The researchers say their study is one of the first to investigate the impact of "irrational beliefs" on consumer behaviour.