Rules of origin exist because governments wish to discriminate amongst
products on the basis of their ''country of origin''. Since the compo
nents and activities that make up the total value added of many produc
ts are not created in a single location, rules to define a unique geog
raphical source for products must be somewhat arbitrary, and inevitabl
y introduce distortions into production and trade patterns as producer
s seek to provide their products with the most favourable origin. This
paper considers the structure of such rules and their economic conseq
uences. JEL no. F13.