Some factors why Shanghai and Singapore is World's largest cargo
and container port resp
Shanghai handles huge volumes of steel and coal which are bulky
cargoes. These materials pushes up the cargo throughoutput
As for Singapore, as PSA has become more price sensitive, it has
helped to maintained its position. Furthermore, since it is a
transhipment hub, any rise in container volume, Singapore stands to
gain. As PSA has become more price sensitive, port war has errupted
bet the 2 Malaysian major ports as well, for the 2 shipping lines
that uses Klang as hub. So, 3 ports in the region might be too
much