Empty pool

An empty pool is the stock of empty containers built up in a region where imports exceed exports, leaving boxes idle after discharge with no outbound cargo to fill them. Trade imbalance creates it: North America and Europe accumulate empties against Asian export flows, so carriers must reposition empty boxes back to load regions at their own cost. Repositioning empties is one of the largest controllable costs in liner operations and shapes per-diem and detention charges that push shippers to return boxes promptly. The empty pool is the container counterpart of a ship’s ballast leg.