The terms of trade for commodities since the mid-19thcentury

This paper shows that there was an improvement in the barter terms of trade for non-fuel commodities vs. manufactures in the late 19thand early 20thcenturies, followed by significant deterioration over the rest of the 20thcentury. However, the decline over most of the 20thcentury was neither continuous nor was it distributed evenly among different commodity groups. The far-reaching changes that the world economy underwent around 1920 and again around 1979 led to a stepwise deterioration which, over the long term, was reflected in roughly a halving of real commodity prices. Tropical agriculture fared the worst, whereas minerals had the best performance, with non-tropical agriculture in an intermediate situation. The increase experienced in the first decade of the 21stcentury may be the beginning of a long-term upward trend, but it is too soon to tell.