The unfair-trade codes of the GATT/WTO are suited to addressing complaints from manufacturing than agriculture. This is because the seasonality and uncertainty of agricultural output, together with substantial use of contracting with factors of production, makes sales at a loss a rational business practice during certain times of the year. This cost dumping induces the use of constructed values in the calculation of dumping margins by the US, which typically generates high duties. The model provides for cyclical dumping arising as a supply phenomenon. This contrasts with cyclical dumping in manufacturing that is induced by demand fluctuations. Copyright 2000 by Blackwell Publishing Ltd.