Weigh Your Options: How Price Format Can Boost Sales Without Changing the Price

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Every grocery shopper has stood in front of a produce display, glanced at a price tag, and made a quick judgment about whether something is a good deal. A Journal of Marketing Research study reveals that this judgment is systematically shaped by something most retailers have never considered strategically: whether the price is listed per unit or per pound. Walk through almost any grocery store, and you will encounter both types of pricing. For example, bananas might be labeled at $0.29 each at Trader Joe’s but $0.55 per pound at Publix. Papayas sold at $3 each at Safeway may appear as $1.50 per pound at Whole Foods.

Researchers Sarah Whitley, Julio Sevilla, and Mathew Isaac demonstrate that the format of the most prominently displayed price—not just the dollar amount itself—significantly shapes how consumers perceive the value of a product and, ultimately, whether they buy it. Critically, the optimal format depends on a single, easily observable product characteristic: its weight.

The Anchoring Effect: Why the Displayed Number Drives Perceived Value

The core insight of this research is that when consumers assess value, they anchor on the nominal value of the most salient price they see—fixating on the raw number (e.g., $1 vs. $2) as a proxy for how good a deal is, even when it is incomplete. This creates a predictable pattern: For products weighing less than one pound, unit-based prices display smaller numbers and therefore appear more attractive (e.g., $0.50 each vs. $1.00 per pound for the same half-pound item), while for heavier products the reverse holds, making weight-based prices seem cheaper (e.g., $2.00 per pound vs. $4.00 each for a two-pound item), despite identical total costs. Crucially, this bias persists even when both price formats are shown simultaneously, as consumers continue to rely primarily on whichever price format is made most visually salient through cues, such as larger font, prominent placement, or distinctive color.

From the Lab to the Store

Across sixteen studies, including multiple experiments and real-world field tests, the authors find consistent support for this effect. In controlled settings, participants systematically preferred unit-based pricing for smaller products and weight-based pricing for larger ones, even when prices were economically identical. More importantly, the field experiments show that this bias translates directly into purchasing behavior. In collaboration with a grocery retailer, simply switching the price format, without changing the actual price, increased sales of sub-pound items by 12%–24% when priced per unit.

A second field study replicated the full pattern: sales of a half-pound product were 90% higher under unit-based pricing, while sales of a two-pound product were 39% higher under weight-based pricing.

A Simple Fix with Real Profit Implications

For retailers, this research provides a clear, actionable set of lessons:

1. First, price format is a meaningful strategic lever: simply making the right format more salient, without changing actual prices or product assortments, can increase sales and improve value perceptions.
2. Second, the one-pound threshold is the key decision rule: products weighing less than one pound benefit from unit-based pricing, while products weighing more than one pound benefit from weight-based pricing.
3. Third, the effect is robust and difficult to override, persisting even when both price formats are visible.

For managers, where every pricing decision counts, this research offers a rare opportunity: a low-cost, immediately implementable change that can have a meaningful impact on the bottom line.

We reached out to the authors to learn more about how this research came together, what it means for the industry, and what surprised them most along the way.

Q: You mention that current retailer pricing (e.g., Trader Joe’s using unit-based pricing for bananas while Kroger uses weight-based pricing) often seems “discretionary or even arbitrary.” Did you have a specific retail encounter or industry conversation that first led you to suspect this arbitrariness was actually a missed opportunity for firm profitability?

A: All of us have had various encounters that made us start thinking about different grocery pricing formats. For instance, Sarah has a very specific memory of once buying a melon from the grocery store, actively checking the price, and thinking, “yep, that sounds like a good deal” because it was a small number. However, at checkout, the melon ended up being three times more expensive than she had thought because the store used a weight-based price, and she had not even noticed and had assumed it was unit-based because that was what she was familiar with.

On the other hand, Julio had noticed these differences in price formatting when grocery shopping and found himself strategically picking the largest items when a unit-based price, rather than a weight-based price, was employed. We started talking about these various interactions and how different stores price different items, which highlighted how arbitrary these pricing strategies seemed to be. We even conducted an analysis comparing the pricing formats used by two major retailers, Publix and Kroger, and noticed very little consistency across products. This made all of us wonder how consumers tend to respond to these different price formats and whether there is a strategic way for retailers to price items based on how consumers perceive these prices.

Q: Your field studies show that changing price format can increase overall sales and average spending per transaction. How should a category manager think about choosing a price format depending on whether their goal is to increase total revenue, average basket size, or purchase incidence?

A: In general, we show that when a particular product price format seems more attractive, this can increase total revenue, but exactly how this increase occurs depends on characteristics of the specific product being considered. For instance, melons typically weigh more than 1 pound, and we should expect to see higher sales if offered at a weight-based versus unit-based price. At the same time, people do not typically buy multiple melons because it may take a few days and/or multiple people to eat just one. Thus, an increase in revenue under weight-based pricing for melons is most likely due to an increase in purchase incidence rather than an increase in basket size.

Alternatively, for a common low-weight staple like bananas (where one banana weighs under one pound), employing unit-based pricing would most likely increase total revenue by increasing the basket size (i.e., the number of bananas purchased) rather than by increasing purchase incidence. If retailers adopted the more attractive pricing format across all products, they should see an overall increase in total revenues. Still, the reason why would ultimately depend on the composition of each individual consumer’s basket.

Q: While this study focused on the “one pound” threshold, you anticipate similar results for kilograms or ounces. For a global retailer operating, for example, across multiple countries, how do you handle products that are “higher-weight” in pounds (e.g., 1.5 lbs) but “lower-weight” in kilograms (e.g., 0.68kg)? Should retailers be looking at consistency to build consumer trust, or is the anchoring effect powerful enough that strategic inconsistency is actually more profitable?

A: Our work suggests that strategic inconsistency might be more profitable. We observed that even in the same retail store in the same country, merchants routinely use different price formats for products in the same food group. Thus, consumers are unlikely to hold a strong belief that a retailer will maintain the same pricing format across different countries. Unless a retailer claims it uses only one pricing format worldwide, it would be normal for retailers to employ different pricing formats based on the dynamics and norms of different international markets. Firms already have to develop different prices for products across international markets based on supply costs and consumer demand, so why not also make price format one of those adjustments?

Q: We often think that once a consumer sees “behind the curtain,” the magic trick stops working. If shoppers become aware of this nominal anchoring bias, or for more price-conscious consumers, does the effect evaporate, or is this a psychological reflex that’s just too hard for the average brain to override in a busy aisle?

A: While each person is different, this does seem to be a fairly strong psychological reflex to override. We do find that when consumers are prompted to evaluate more information when judging the value of an offering, less attention is paid to the nominal price. Yet, even then, the anchoring bias still occurs! Furthermore, it seems to persist among price-conscious consumers (i.e., “tightwads”) and in contexts where consumers are presented with both price formats simultaneously. Even though we discovered and published a paper on this anchoring bias, the coauthor team is still sometimes guilty of inadequately accounting for the price format, even when we shop now!

Unless consumers actively think about this anchoring bias and guard against it when shopping, our brains often rely on the most salient price as a shortcut (e.g., “low prices are better!”) in decision making. Because people are more time-constrained than ever, the need to make quick grocery decisions (whether online or in the store) is ever-present, suggesting that this nominal anchoring bias may occur even when consumers are aware of it.

Q: Some might argue that choosing a price format specifically to make a price look “cheaper” is a form of consumer manipulation. Where do you draw the line between “effective marketing” and “deceptive pricing”? How can a Chief Marketing Officer (CMO) defend these formatting choices to a board focused on ESG (Environmental, Social, and Governance) goals?

A: This is a valid question. In our studies, we were careful to present both price formats (i.e., unit-based and weight-based) to participants simultaneously to ensure that they had full information to make an informed judgment. In fact, at least 18 U.S. states require both types of prices to be presented to consumers (National Institute of Standards and Technology 2024). However, even when both price formats are present, consumers still tend to focus on whichever price is featured more prominently. While some might argue that choosing an advantageous price format for products is coercive, a CMO could argue that it actually benefits consumers, depending on the product it is used for.

In our studies, we primarily employ fruits and vegetables, for which employing the price format that is better from a retailer standpoint (in that it increases sales) could be considered a valuable nudge that encourages healthier eating and thereby increases societal well-being. However, if a retailer used a particular price format to drive up sales for less healthy foods like chocolate, candies, or baked goods, then this strategy might conflict with ESG goals. We note in the paper that policymakers should consider the influence of price format salience in the future when developing price labeling standards for the industry, rather than leaving this decision up to individual retailers.

Q: More and more people shop for groceries online. In a mobile shopping environment with limited screen real estate, the salience of a price is often dictated by app architecture and sorting algorithms. If a consumer sorts by “lowest price,” does unit-based pricing give lower-weight products an algorithmic advantage in “lowest price” sorting?

A: This is an interesting question. Typically, when consumers shop for their groceries online, they search for a particular product (e.g., bananas, melons), so it is unlikely that they will see lower-weight and higher-weight products (e.g., both bananas and melons) simultaneously in their search results. Instead, they will see different varieties of the same product. If a retailer offers multiple varieties of a single product (e.g., different brands of bananas), and those varieties were to be priced using different formats, then some varieties would certainly have an algorithmic advantage based on price format (when sorted by “lowest price”).

However, this does not seem to be typical. If a retailer is selling a specific product online, all varieties of that product tend to be priced using the same format. Lastly, it is important to keep in mind that the direction of any algorithmic advantage would depend on whether an item generally weighs more or less than a single unit (e.g., 1 pound, 1 kilogram, 1 ounce). For lighter-weight items (i.e., less than 1 unit of weight), price sorting features would provide an algorithmic advantage for unit-based prices. However, that advantage would flip for products that are higher-weight (i.e., weigh more than 1 unit). Again, consumers would likely see this type of price-comparison sorting only if they conducted more holistic or general searches across many product categories rather than focusing their search within a single product category (e.g., within bananas), which is much more common in online grocery shopping.

References

National Institute of Standards and Technology (2024), “A Guide to U.S. Retail Pricing Laws and Regulations,” (updated July 31, 2024), https://www.nist.gov/pml/owm/laws-and-regulations/usretail- pricing-laws-and-regulations.

Sarah C. Whitley, Julio Sevilla, and Mathew S. Isaac (2025), “Units or Pounds? How Anchoring on Salient Price Information Influences Perceptions of Product Value,” Journal of Marketing Research, 62 (5), 876–94. doi:10.1177/00222437251340367

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