I just listening to Eli Noam giving a talk that claimed that Google was the world’s largest media company. The big PDF appears to be the base presentation he was working off. The slide that he used showing Google to be the largest media company, had Time Warner and Telecom Italia in it. He made references to HHI, but it is not clear how he claims that Google (a search engine and advertising company), Time Warner (a media and cable company) and Telecom Italia (a telecom company) can be in the same market and how their market shares can be calculated. When I questioned this, I was advised that the methodology is in two books, one for the US and one for the rest of the world.
In the US, many legal and policy battles have been fought on the definition of markets. The famous Cellophane case rested on a definition of the “relevant market” as “the market for flexible packaging materials.” In media cases, the debates have been about whether newspapers constitute the relevant market or whether TV and radio have to be included. These debates are about things that are substitutes for the end users: “I get my news from the radio, no longer from newspapers.” But how one claims that Google is a media company, not the New York Times that I read on the web puzzles me. Whatever fancy methods academics come up with, common-sense has a place in the real world.