Go to www.oligopolywatch.com, which is a rather interesting site about (what else?) oligopolies. There's stuff that talks about the case study the rest of you have done (which I haven't) . It is suggested that firms prefer to be in an oligopoly rather than a monopoly. Compare Microsoft with Coke and Pepsi. Who attracts more consumer ire? How's this for a new term? The author of the site proposes that an "oligonomy" is a situation where the same companies act as oligopolies and oligopsonies.