Global Market Effects of Alternative European Responses to Genetically Modified Organisms. — Current debates about genetically modified organisms (GMOs) in agriculture reveal substantial differences in the perception of the associated risks and benefits. Genetically modified crop varieties allegedly provide farmers with agronomic benefits, but environmental, health and ethical concerns are also being raised. This paper discusses the ways in which the emergence of GMOs could lead to trade disputes between Western Europe and the United States. It then uses an empirical model of the global economy to quantify the effects on production, prices, trade patterns and national economic welfare of specific policy and consumer responses to GMOs in Western Europe.