Even as the volumes entering the main ports of San Pedro Bay in California have declined since a peak in May, containerships are yet again waiting in longer lines at anchorage before discharging their containers.

In the meantime, on the opposite coastline, exports of empty containers for the first time ever exceed loaded exports. This is yet another sign of the times in today’s crazy world of logistics.

The number of empties leaving the US east coast was highest in May, but as loaded ...