Kristina Shampanier

Who they are

This page records what can be verified from the papers. Biography beyond the cited work is not recorded, by rule.

On the 2007 paper, the publisher's record lists Shampanier at the Massachusetts Institute of Technology, in Cambridge, Massachusetts. On a later paper, from 2017, the record lists her at the Analysis Group in Boston. Both listings are the affiliations printed at the time of publication and say nothing about what came between or after.

She is first author of the paper the zero price effect is cited to, and second author of a later paper that revisits free pricing from a different angle. That is the whole documented footprint used here.

Key papers

Shampanier, K., Mazar, N., & Ariely, D. (2007). "Zero as a Special Price: The True Value of Free Products." Marketing Science, 26(6), 742-757. First author. Abstract read; the paper was not read in full.

Mazar, N., Shampanier, K., & Ariely, D. (2017). "When Retailing and Las Vegas Meet: Probabilistic Free Price Promotions." Management Science, 63(1), 250-266. Second author. Abstract read.

Key ideas

The central claim of the 2007 paper is that decisions about free products differ in kind from decisions about cheap ones. Standard theory says people choose the option with the highest cost-benefit difference. The authors propose that for free products people do not simply subtract costs from benefits. They perceive the benefits of a free product as higher. In the abstract's words, people act as if zero pricing of a good not only decreases its cost but also adds to its benefits.

The design is the part to remember. Two products are offered and the difference between their prices is held constant. In one condition the cheaper product costs a low positive amount. In the other it costs nothing, and the dearer product's price falls by the same amount. A standard cost-benefit rule predicts the same choices in both conditions. The authors found that in the zero condition dramatically more participants chose the cheaper option and dramatically fewer chose the more expensive one.

The version most readers meet is Ariely's retelling in Predictably Irrational (2008). A Lindt truffle against a Hershey's Kiss, at 15 cents and 1 cent, drew 73 per cent for the truffle. With the Kiss free and the truffle at 14 cents, 69 per cent took the Kiss. A ladder run priced the Kiss at 2 cents, 1 cent and nothing, and showed that two cents to one made no difference while one cent to nothing made a large one. The book gives no sample sizes for these runs.

After documenting the basic effect, the paper proposes and tests several psychological antecedents: social norms, mapping difficulty and affect. The abstract states that affect emerges as the most likely account. That statement is hedged, and it is a statement about relative likelihood among the three tested, not a demonstration that affect is the whole story.

The 2017 paper, on which Shampanier is second author, looks at a related promotion. Retailers sometimes offer a chance of getting the whole purchase free, which is a probabilistic free promotion. Across six experiments in the field and the laboratory, the authors found consumers were more likely to buy a product promoted that way than the same product promoted with a sure discount of equal expected value, and they bought more of it. The preference seemed to be mostly due to a diminishing sensitivity to prices, and the authors report that the zero price effect, transaction cost and novelty were likely not implicated. A later paper by Celia Gaertig and Joseph Simmons, in 2025, found that such promotions beat sure discounts mainly when the sure discounts are or seem trivial.

Two points about reading this work. First, the book and the paper are not the same source. The book's bibliography lists the zero-price chapter's source under an earlier title, and the published title is the one above. Second, the strength of the claim is in the designs, and the book's runs do not report the sample sizes that would let a reader weigh the percentages. The designs can be cited. The percentages are the shape of the result.

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