A bag of chips feels lighter than it used to, and the price on the shelf has not moved. Shoppers have suspected for years that packages are shrinking, and a study in the journal Marketing Science now puts a number on what happens next. Researchers found that the price per unit rose by about 12% in the year after a package got smaller.
That 12% figure comes from a Feb. 27, 2026, news release by INFORMS, the group that publishes the journal. The study, “Shrinkflation and Consumer Demand,” was written by Aljoscha Janssen of Singapore Management University and Johannes Kasinger of Tilburg University. Unit price here means the price per unit of volume, so a smaller package at the old price works out to a price increase even when the sticker never changes.
A Decade of Scanner Data on Millions of Products
The authors worked from NielsenIQ retail scanner data covering 2010 to 2020, according to INFORMS. The data included millions of products sold in U.S. stores. NielsenIQ is a Chicago-based market research firm that was founded in 1923 as ACNielsen, and it is known for tracking what shoppers buy.
Money basics are the subject of a list of money lessons many people wish their parents had taught them. The study appeared in Marketing Science, a bimonthly peer-reviewed journal that INFORMS has published since 1989. The release dates the study to February 2026, so the findings are less than nine months old, even though the data they rest on ends in 2020.
Downsizing Outnumbered Upsizing
About 1.9% of products in the data were downsized, versus just over 1% that were upsized, INFORMS reported. Measured by total sales, downsizing was more than five times as common as upsizing, according to the release. Downsized products, in other words, accounted for a bigger share of sales dollars than of product counts. Products that cost more than they seem to are also the subject of Frenz Hub’s list of outrageously expensive products Americans are overpaying for.
Size increases went the other way on price. The release says they were linked to slight decreases in price per volume. A larger package, in other words, tended to come with a small unit-price break, while a smaller one came with the opposite. As a counterpoint, Frenz Hub’s list of things that are actually getting cheaper covers prices heading down.
The 12% Jump in Price Per Unit
Prices per unit of volume rose roughly 12% in the year after a size reduction, the authors found. Kasinger explained the pattern in the release: “In most cases, package sizes shrink without a corresponding decrease in price.” Shoppers end up paying more for each ounce, even if the shelf tag looks the same.
The figure is an average across the whole data set, not a promise about any single item, so individual products can land above or below it. What the release does say is that the average pattern across the data pointed in one direction, and for anyone looking to trim a grocery bill, Frenz Hub’s 26 easy tips for saving money fast offer more places to start.
The cost of that pattern shows up at the register. Each extra cent per ounce is multiplied by every package in the cart. Money habits that keep a budget steady are the subject of a list of habits of people who never seem to run out of money, and the same logic applies to reading labels.
Shoppers Notice Price More Than Size
The study also measured how shoppers react. Janssen said in the release that a 1% increase in price reduces sales by about 1.2%. A 1% size reduction, by comparison, cut sales by roughly half as much. Shoppers appear to push back harder on a higher sticker price than on a smaller box.
Janssen called the consumer psychology behind shrinkflation “fascinating,” and said shoppers tend to focus on per-unit cost and buy more units. That gap suggests why a manufacturer might shrink a package instead of raising its price.
Cereals, Detergents and Snacks Lead the List
Shrinkflation was most common in cereals, detergents, snacks and sanitary products, according to the release. The findings describe a pattern across the market, not the practice of any one company.
The term itself is a blend of “shrink” and “inflation.” Wikipedia’s shrinkflation page credits economist Pippa Malmgren with the first use of the term in its current sense. It cites examples such as Danone shrinking yogurt cups from 8 to 6 ounces in 2003 and Häagen-Dazs cutting ice cream cartons from 16 to 14 fluid ounces in 2009.
What the Government Says and How to Spot It
Not every analysis sees a large effect on the overall economy. The same Wikipedia page reports that the Bureau of Labor Statistics says product downsizing has a minimal effect on overall prices, averaging about 0.01% per year, while adding that shoppers may still notice it at the grocery store. The two findings are not in direct conflict: one measures the economy as a whole, and the other measures what happens to a single product after it shrinks.
The simplest tool for catching a change is the unit price on the shelf tag. Wikipedia’s unit price entry says stores usually post the price per unit of measure below the food, next to the total price. Comparing that number from one trip to the next shows whether a familiar product has quietly gotten more expensive. Noting the net weight printed on a favorite box is another low-effort check.
This article was produced with AI assistance and edited for accuracy against the sources linked above.
Image: Raysonho – CC0/Wikimedia Commons
