Steve Viscelli of the School of Arts & Sciences said the U.S. supply chain is built on unpaid labor by port truckers waiting to pick up cargo from shipping containers. “The port truck driver, for decades now, has basically been the slack adjuster in the whole system,” he said.
https://www.bloomberg.com/news/articles/2021-10-21/biden-tackles-supply-chain-crisis-with-few-tools-clock-ticking Bloomberg