Economic uncertainty and shifting consumer behavior weighed heavily on U.S. supply chains in December 2025, pushing logistics activity to its weakest levels in months.

Florida Atlantic University's Logistics Managers' Index (LMI) — which measures expansion and contraction in U.S. supply chains based on warehouse and transportation capacity and inventory levels — came in at a 54.2 score for the month of December, down from December 2024's 57.3 figure, and marking the index's lowest score in 13 months. The LMI's inventory score also fell by more than 17 points to 35.1 between November and December, although the decrease was attributed to a relatively busy holiday shopping period.

But even with strong holiday retail sales to close out the year, high earners likely drove a significant portion of those numbers, FAU noted, while sales made to lower earners stagnated, as many families restricted their budgets to necessary spending. 

“At a high level, the strong sales are a good sign," said FAU associate professor of supply chain management Steven Carnovale, Ph.D. "The lingering question is which segment of the consumer market is buying."

Economists have spoken frequently in recent months of an emerging "K-shaped" economy, where high earners have been propping up increases in total household spending, while lower income families have spent substantially less in the face of growing economic instability. Speaking at the National Retail Federation's 2026 "Big Show" conference in New York City on January 13, Bank of America senior economist David Tinsley estimated that money coming into higher-income households was up 3% in 2025, and just 1% for low-earners.

Signs of this trend were clear even before the holiday shopping season. According to real estate and investment management company JLL, households earning over $150,000 increased their planned holiday spending by 26% in 2025, while households under $50,000 cut their spending by nearly a quarter. Walmart CFO John Rainey spoke of that disparity at a Morgan Stanley conference in early December, when he acknowledged that the wage growth gap between upper, middle and lower class families is as wide as it's been in nearly a decade.