Perhaps this is one of the central subjective questions, but....How much debt has to be written off?

I looked around a little for current estimates of M2, M3, derivatives, etc, but didn't really find what I was looking for. Anyone have a good source?

Cypherdoc, do you have any theories or data about how much debt has to be defaulted on before a sustainable level is reached? What is a sustainable level, and is there long-term data to support that number (ie, can we simply look at leverage levels before the debt/securitization explosion of the 90s and 2000s as the "norm" that we will/should return to, and calculate the necessary debt-money supply deflation on that?).