The impact of consumer demand for quality on the agricultural and food system is an increased emphasis on quality differentiation but not all in the direction of upgrading quality.  The more elite market segments are thriving and reaching growing numbers of consumers but the basic price/quality markets remain strong.  Most recent economic studies find that consumers are willing to pay for food safety and other quality attributes, and for information about them.  The magnitude of the valuations varies by food product, attribute, country, and study design.  This literature and a case study of genetically modified foods suggest that consumer demand has a strong effect on agricultural and food trade.