I am biased to believe a good analysis, and this is one of the best ever published. The author takes great care to ensure that his data and methods are clearly laid out. He critiques his own findings, and points out weak points in the argument with the same vigour as when expounding his conclusions. In short, he adheres to the principles of good science and objectivity.The text and observations are rich and dense, with no fluff or emotive arguments. The shear scale of his analysis and sources are impressive. Even when exploring hypothetical causes of his findings (which is opinion, not science) he draws on many respected authors and credited sources.This is one of the most significant studies and books I have ever read.