Origins of the financial/economic crises

Economic historians will have some real good time writing about this Great Recession--for many, many years down the road, and will also offer convincing answers to people like my mother who asked me last December, "how come nobody knew?" that such a crisis was round the corner ..... well, here is one explanation of how things soured, from four months ago, by Jeffrey Frankel, who is the James W. Harpel Professor of Capital Formation and Growth at Harvard Kennedy School