Collapse: How Societies Choose to Fail or Succeed by Jared Diamond.
Dr. Diamond is a professor of geography at the University of California, Los Angeles. His last book Guns, Germs, and Steel was awarded the Pulitzer Prize. It was a study of factors affecting the buildup of societies. I haven't read it, so I'll shut up about it now.
In Collapse, Dr. Diamond has identified five key factors that can possibly lead to the collapse of a society. He has applied the comparative method to examine past cultures and present cultures to see the effects of one, a few or all of these factors on the cultures.
He explains his method of analysis much better in the very first chapter than I can here, and he guides you into each cultural study. His prose is plain and well written for an easily accessible reading.
This morning I finished the chapter on Montana and began the next on Easter Island, and it's been a fascinating read already.
Although the main title of the book, Collapse is provocative, the subtitle of the book is the more illuminating part of the title based on what I've read so far.