Anderson writes about people who use living history as a way to "expiration" with the past, as a research tool, and of course, for pleasure. The book is a bit dated by now. It could use a substantial revision or a new edition. That said, it is an excellent introduction to the culture of living history and the motivations that many practitioners feel. It is a quick read and a good place to start reading about living history, plus EVERYONE writing about living history/reenacting cites Anderson's book.
One of my professors wrote this book and for anyone into living history, this is a great book to read as it analyzes the different types of living history, its functions and why people participate in it. He writes the book from a personal perspective, adding in his own experiences with living history. A really interesting read.