http://www.hbs.edu/research/pdf/09-060.pdf Thanks to Ezra Klein’s blog on washingtonpost.com for the link – the paper is a great read (once you get past the economics) to understand exactly the mortgage back securites (MBS) market fell apart – essentially it was due to (1) bad assumptions of defalut rates, (2) poor ratings of each MBS pool byRead… Read more »