I own the 5th and 6th editions. The author, Bill Domhoff ' actually makes useful changes through the editions. Not as a way to make big bucks off of students who "must"(not really) buy the newest edition that their teachers recommend. He updates it with the latest news on the power struggles. And the newest edition shows his hope in Barack Obama's challenges to the corporate community.You see, nobody likes to admit that there is a class system in the United States. Bill Domhoff shows that there clearly is a corporate community that propagates itself through joining exclusive clubs, expensive private schools, and through this, having extensive connections to other people in the upper class. It has been in place since before the civil war. Yes, that's right. The age of the robber barons. And if this isn't interesting enough, Domhoff shows how they influence public policy, and even public opinion. You'll find yourself thinking twice about many of the bills that are in the news. Because chances are, they are a product of the vicegrip that the corporate community has on our country.Anyway, I think that this book makes understanding the power structure in the United States a lot easier, and it makes sense of a lot of the things you hear. It in slightly politically charged, but it has quite a bit of facts, and is a very sociological study of power in america.