Freight ships are one of the best examples I know of a service whose demand is derived from the simple need among exporters and importers to transport their products around the world. So when the global economy changes gear and the chill-winds created by record high oil prices and a slowdown in consumer spending start to bite, it is more or less inevitable that the major shipping businesses will feel the pinch.

The Telegraph carries a report on this today. Ships are leaving Asian ports not full to to capacity a sign perhaps that the increased costs of shipping products is starting to limit demand for freight services.

Apparently the index to watch out for is the Baltic Dry Bulk Index - a measure of commodity-shipping costs - and this bell-weather measure has fallen sharply in recent days hinting of a shift in the balance between supply capacity and demand for ships to move the major raw materials by sea.

Too much freight capacity in the industry? Or a really important lead indicator that 2009 will be a really tough year for the global economy?