The origin and consistency of the ton-mile metric in the shipping economics

The aim of this paper is to investigate an underpinning of the conventional maritime economics, supply-demand framework, and measurement of shipping services in particular. The ton–mile metric is frequently employed as a measure of demand in both academia and professional readings. On the other hand, the ton–mile measurement approach has various drawbacks and inconsistencies that are thought to be negligible or simply ignored. The incompleteness of the ton–mile metric approach, which is usually taken as granted, is discussed in terms of its origin and historical presence in the literature. Assumptions behind the approach are investigated, and practical limitations are revisited.