Are they? News to me. Sherlock Shamelessly reproduced here from fellow ET'r travis: (thank you) "Everyone knows that something can't be done, and then comes one man, who doesn't know that it can't be done, and he's the one who does it." - Albert Einstein
There is a discussion of leading indicators in LeBeau and Lucas's book, http://www.amazon.com/exec/obidos/tg/detail/-/1556234686/ They are particularly fond of one specific leading indicator. Dig in and read, you may enjoy their coverage. If you confine your studies to pp 80 thru 100, you'll find it.