Global commodity markets are affected by a variety of government policies that may expand or lower overall supply and as a result affect world prices for the specific products concerned. Market failures and market structures (market power along the value chain) also affect supply. This paper...

World commodity markets-and particularly the markets for agricultural commodities-remain highly distorted despite the wave of liberalization that has swept world trade since the 1980s. Some markets for commodities are characterized by imperfect competition. Where monopolies or oligopolies in...