Source: WTO. United Nations, Review of Maritime Transport.

International Seaborne Trade and Exports of Goods, 1955-2007

The growth of maritime transportation is strongly correlated with the growth of international trade as maritime shipping and ports are the main physical support for international trade transactions. From about 800 million tons of loaded cargo in 1955, maritime traffic exceeded 8.0 billion tons for the first time in 2007, which represents 32,500 ton-miles. Yet, maritime shipping is subject to fluctuations as commercial opportunities change. Major fluctuations in the value of exports in the 1970s and 1980s were mainly linked with economic recessions associated with the first and second oil shocks (1973 and 1979). More recently, the development and rapid diffusion of containerized maritime transportation was linked to a growing trade of value-added commodities. For every $1,000 of exports, there is one ton of freight being shipped by maritime transportation. From the late 1990s, a growing disconnect took place between the volume and value of maritime trade, mainly the outcome of the increasing sophistication of goods manufactured in Pacific Asia, rising energy (oil) prices as well as the fragmentation of production since parts could be traded several times.

Looking at the ratio between the value of exports per volume of seaborne trade underlines that until the first oil shock in 1973 it remained constant, underlining little changes in the composition of maritime shipping. The first two significant changes in this ratio correspond to the first and second oil shocks, implying that higher oil prices directly impacted the global value of exports. Afterwards, the steady growth of the ratio is mainly attributed to the growth in the containerized trade of merchandises, particularly at the beginning of the 21st century.