Steadily worsening cargo congestion.
Check it out:

U.S. Labor Secretary Tom Perez planned to hold a second round of talks with shipping company executives and union leaders for 20,000 dockworkers on Wednesday, seeking to broker a deal to end months of labor turmoil clogging cargo traffic at 29 West Coast ports.

Perez was sent to San Francisco as an emissary of President Barack Obama, who has come under mounting pressure to intervene in a conflict that has reverberated through the trans-Pacific commercial supply chain and, by some estimates, could cost the U.S. economy billions of dollars.