London, Jan 17 (IANS): Common sense suggests that warning labels on products like cigarettes and medications would encourage people not to go for them. Wrong.

Research suggests that warning labels can actually have the opposite effect, making the product more appealing.

“When there is a time lag between reading a warning and then buying or consuming the related products, the warnings may encourage trust in the manufacturers of potentially dangerous products - making them less threatening,” said Yael Steinhart of Tel Aviv University's Recanati Business School in Israel.

Although warnings may immediately decrease consumption but over a period of time, they paradoxically promote trust in a product and consequently lead to more positive product evaluation and more actual purchases, said the study published in Psychological Science.

In one experiment, researchers showed smokers one of two ads for an unfamiliar brand of cigarettes - either with or without a health warning.

When smokers were told the cigarettes would arrive the next day, the warning worked - decreasing the number of cigarettes purchased by an average of 75 percent compared to a group that was not shown the warning.

“When smokers were told the cigarettes would arrive in three months, the warning backfired - the number of cigarettes purchased increased by an average of 493 percent compared to a group that was not shown the warning.

The findings have important implications for regulators and managers in fields including consumer products, healthcare, and finance to help improve the efficacy of warning labels, said co-authors professor Ziv Carmon of INSEAD in Singapore and professor Yaacov Trope of New York University.