New methods for mapping media concentration: network analysis of joint ventures among firms

Measures of media concentration typically rely on two primary indices: CR4 and HHI. These indices are based on the market share of the top firms as well as the share of total revenues for top firms. These indices only serve as an adequate representation of media concentration sectors if one assumes that the top firms are competitors. However, these measures do not adequately capture the degree to which top firms work together through joint ventures or other shared interests. By using network analysis, this article illustrates the joint ventures that exist among the five largest media firms (Comcast, the Walt Disney Company, National Amusements, AT&T/WarnerMedia, and Fox/News Corporation). We argue that this type of analysis can supplement existing measures of media concentration and may also be useful for policy debates, particularly in reviews of proposed mergers.