The study of international trade in agricultural products has developed rapidly over the past fifty years. In the 1960s the disarray in world agriculture caused by domestic price support policies became the focus of analytical studies. There followed attempts to measure the distortions caused by policies also in developing countries and to model their impact on world agricultural markets. Tools were advanced to explain the trends and variations in world prices and the implications of market imperfections. Challenges for the future include analyzing trade based on consumer preferences for certain production methods and understanding the impact of climate change mitigation and adaptation on trade.