Audience concentration in the media: cross-media comparisons and the introduction of the uncertainty measure

This article examined how audiences respond to item abundance by analyzing audience concentration of magazines, cable television networks, radio networks, and broadcast television networks. The primary finding is that there is a positive relationship between item abundance and the degree of audience concentration measured by uncertainty ratios. As item options in newer media increase, the finding is important for two reasons: diversity issues related to audience behavior and diversity policy issues. The efforts to promote item diversity by policy-makers can be undermined by the result that audiences concentrate more highly on a smaller portion of items with an increase in item options.