Relative Price of Primary Commodities Many developing countries export primary commodities (i.e., agricultural products and minerals), whereas industrial countries export manufactured products. Shown here are the prices of various primary commodities relative to an overall manufacturing price, from 1900 to 1998. The relative prices of some primary commodities have fallen over time (panel a), whereas other commodities have had rising relative prices (panel b). Other commodity prices show no consistent trend over time (panel c).