Study: Warning Labels Don't Always Work

By Jane Farrell

Although warning labels are meant to warn consumers of a product's potential dangers, they may actually decrease awareness of those dangers over time

 A new study by Dr. Yael Steinhart of Tel Aviv University's Recanati Business School, along with Prof. Ziv Carmon of INSEAD in Singapore and Prof. Yaacov Trope of New York University, has shown that when there's a time lag between reading the warning label and buying the product, warning labels can actually have the opposite effect.    As time passes, the researchers found, the warnings may actually encourage trust in the s of potentially dangerous products. Published in Psychological Science, the study findings could help improve the efficacy of warning labels.

  "We showed that warnings may immediately increase concern and decrease consumption," said Steinhart. "But over time, they paradoxically promote trust in a product and consequently lead to more positive product evaluation and more actual purchases."

 Steinhart said the researchers' findings have significant for regulators and companies such as product managers, including healthcare and finance.   For their study, the 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. But 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.

 In another experiment, the researchers showed women ads for an artificial sweetener, either with or without a health warning. When women were given the chance to order the sweetener right away, the warning worked — decreasing the packages of sweetener ordered by an average of 94 percent compared to a group that was not shown the warning.

But when women were given the chance to order the sweetener just two weeks later, purchases increased by 265 percent compared to a group that was not shown the warning.   As a result, the researchers said, they concluded that companies that want to inform customers of risks should make sure warnings are seen, or repeated, just before products are bought or consumed.