When the first choice isn't available, why don't consumers choose the obvious second choice?

"Close second choices are an important consideration when a consumer makes a purchase decision and then learns that their selection is unavailable (out-of-stock, discontinued, just sold)," write authors Wendy Attaya Boland (American University), Merrie Brucks, and Jesper Nielsen (both University of Arizona). "In many cases, consumers cannot (or prefer not to) wait until their selected item becomes available; therefore they are likely to reconsider the options that are available now."

Even though the obvious choice would be a product that came in as a close second, the authors discovered that up to 60 percent of consumers are likely to reject the runner-up option and select a lower rated (and previously rejected) item. "We found that making a choice between two close options places additional emphasis on the features that differentiate them, making these attributes seem more important to the consumer in a subsequent decision," the authors write.

By way of illustration the authors describe a customer who is shopping for a new pen. After considering his options, the consumer decides he wants an extra fine, felt-point pen and finds two pens that possess that attribute, one with blue ink and one with black. "Although ink was not a major consideration in the original choice, the consumer must choose between them and decides on the blue ink pen," the authors explain. "However, at the checkout line the consumer learns that the blue ink, extra fine, felt-point pen is out-of-stock. And, instead of selecting the black ink, felt-point pen, the consumer instead selects a ballpoint, blue ink pen, giving up the attribute (extra fine, felt-point) that was originally most important to his decision." In that situation, blueness replaced "extra-fine, felt point" as the most important attribute. The authors call this "the carryover effect."

In several experiments the authors found that the carryover effect is strongest when consumers narrow the field by dismissing all but two options.