The news
The Justice Department has subpoenaed four containerboard makers as part of an antitrust investigation into the pricing and sale of containerboard and related products. The companies are Smurfit Westrock, International Paper, Packaging Corporation of America and Cascades. A grand jury in the Northern District of Illinois issued the subpoenas in September.
Containerboard prices are about 20% higher than a year ago, following three rounds of price increases announced by the four producers.
The same district is also hearing a civil class action accusing major producers of conspiring to raise prices.
The details
The grand jury investigation adds a criminal dimension to existing allegations of price-fixing in the industry. Analyst Adam Josephson of Sakonnet Research said the subpoenas suggest prosecutors are examining possible agreements among competitors. He found no recent Justice Department price-fixing prosecutions involving US containerboard producers.
All four companies said they are cooperating with the investigation.
Smurfit Westrock said it believes its practices comply with US antitrust laws.
The civil class action, filed in July 2025, names producers including Cascades, Georgia-Pacific and Pratt Industries. In September, Judge Mary Rowland denied the defendants' motions to dismiss, finding sufficient allegations of a potential conspiracy for the case to proceed.
Smurfit Westrock was dismissed from the suit in October 2025, though units of its predecessors, Smurfit Kappa and WestRock, remain defendants.
The defendants deny wrongdoing.
The latest round of price hikes faced widespread pushback, including from AICC, the Independent Packaging Association. Smurfit Westrock described this year's cost inflation as “unprecedented.”
Smurfit Westrock said price increases typically take effect after a lag of three to six months.
Its pricing clauses “may not in all cases be effective to offset rising costs,” the company said.
Box prices have also climbed 9% since April, the fastest rise since 2021. The producer price index for corrugated and solid fiber boxes rose to 506.1 in September, up 8.9% from a year earlier, Bureau of Labor Statistics data show.
The index barely moved from August 2025 to April 2026, then rose every month from May.
The last faster five-month gains came in late 2021, when box prices rose as much as 12%.
(Photo: Remy Gieling / Unsplash)
