ABSTRACT
The reliable source of diversity and richness in US mass media content is diversity of ownership of the media and a public attitude that accepts the legitimacy of a rich marketplace of ideas, including unconventional and anti-establishment ideas. In the simple village trade in turnips of Adam Smith's marketplace, farmers may have been tempted to sell poor-quality turnips at exorbitant prices. Despite the vast number of local media outlets, the actual range of available ideas and serious information is relatively narrow, due to the nature of ownership and media economics, with a resulting homogenization of content. The US media are becoming more homogenized in content and structure at the same time that the population is becoming larger and more diverse and confronted with rapidly changing circumstances. A wide collection of diverse knowledge and ideas in the media comes from a widely diverse set of individuals among whom there are significant differences in sincerely held ideas and values.
