In this chapter we have looked at sea trade from the viewpoint of the countrieswhich trade.
There are 100 countries that trade by sea, but some are much bigger
than others. In 1991 the USA headed the list with 838 mt of imports and exports,
while Cambodia, the smallest, reported trade of only 106,000 tons. When we looked
for an explanation of the volume of a country’s trade it was clear that the level of
economic activity, measured by GNP, was by far the most important. Two other
explanatory variables, the size (area) of the country, and its natural resources make
a small contribution, explaining about a quarter of the variation in trade volume.
This does not mean they are unimportant, but rather that their impact on trade
cannot be reduced to a simple general rule. Population size, it seems, has no