Highlighting the risks of a behavior—smoking or taking a medication, say—ought to make people think twice about using a product. But a series of experiments we conducted reveals that sometimes just the opposite is true: A warning label can increase a product’s appeal. This happens when there’s a lag between delivery of the message and a decision about buying, consuming, or assessing the product. Why? The mere inclusion of a warning builds trust, because consumers feel that the seller is being honest—and over time that trust becomes more prominent, while the substance of the warning fades.
A version of this article appeared in the October 2013 issue of Harvard Business Review.
