L’ipotesi Prebisch-Singer 50 anni dopo:che cosa abbiamo capito? / The Prebisch-Singer thesis fifty years later: what have we learned?

As regards the thesis that the terms of trade between primary commodities and manufactured goods tended to deteriorate during the twentieth century, econometric analyses based on the Grilli-Yang series have not produced decisive results. Many of these have, however, one point in common: the phenomenon, when present, is not continuous over time, but is concentrated in short periods of structural change, a fact which makes it extremely difficult to forecast deteriorations in the future. Work carried out more recently has highlighted the important role volatility in the terms of trade of primary commodities plays in conditioning any trend deteriorations. Leaving aside empirical results regarding deterioration in the relation between the prices of primary commodities and manufactures, we believe that the policy insights provided by Prebisch and Singer remain substantially valid today: specialization in the agricultural sector or mining industry have so far not led to external economies able to drive other manufacturing sectors.