I have no clue how many times/places I've answered this one (went to my profile and checked - it's three now. *laughs*) My younger brother is a burgeoning securities broker whose lovely wife bought him Freakonomics for Christmas. He bought me a copy for my birthday a week later and insisted I read it so he would have someone with whom to discuss it. I read the book pretty quickly (I don't think the discussion wiill ever be over) and read the article on SLD in the back. I started some research, did some other reading and thus, here I am.