Huge trade imbalances between Asia and the big consumer markets in North America and Europe mean that millions of empty containers have to be repositioned each year, a challenge at the best of times but an absolute nightmare when cargo volumes are so strong, ships are running late, and a shortage of truck drivers is adding to the disruption.

With far more consumer goods exported from Asia to North America and Europe than in the reverse direction, empty containers have to be returned to load ports where they are urgently needed for the next consignments waiting to be shipped to the big consumer markets.

Normally, this process is barely noticed, but in these extraordinary times, empty containers have become a flashpoint for frustrated shippers and others struggling to move products from A to B. In the US, furious farmers based in the mid-west, who are unable to get their hands on containers needed to move agricultural produce to the ports and onwards to overseas markets, cannot understand why containers are being sent back from the US to Asia empty, rather than loaded with grain, rice, or other foodstuffs. To put this into perspective, of the 9.2m teu handled by the Port of Los Angeles in 2020, the equivalent of 2.8m teu were empty. That compares with 1.5m teu of loaded outbound boxes. In August 2021, the port moved 954,000 teu, of which 367,000 teu were empty.