The transshipment box that counts twice

Every few months a port publishes a record throughput figure and a trade journal calls it a vote of confidence in the region. Sometimes it is. More often I want to know how much of the figure is transshipment, because a transshipped box is counted more than once, and the number then says less about local trade than it appears to.

A container arriving at a hub on a large ship, waiting two days and leaving on a smaller ship is lifted off the first vessel and onto the second. Most ports report this as two moves, or two TEU for a 40-foot box.