External Trade

Abstract

Because it has long been an important source of revenue to governments, external trade provides more statistical material at an earlier date for most countries than does any other economic activity. Some statistics, indeed, go back to mediaeval times. Unfortunately, however, it was the standard practice until some time in the nineteenth century, to record the aggregate values of trade in terms of officially fixed values for each commodity (or, at any rate, for most comodities). Since these were not always kept up-to-date, the aggregates tended to become increasingly misleading as a representation of the actual values of imports and exports.¹ For this reason, the statistics are only shown here from the time when declared or computed actual values were used, or from which estimates of these values have been made.