It is generally agreed that our current financial mess was precipitated by the sub-prime mortgage fiasco. The system was already burdened by too much debt to absorb those new losses. The commentators have moved on to the American hobby of assigning blame: to President Clinton and the Democrats for forcing the banks to offer high-risk loans to the poor, the bi-partisan officials for deregulation, and to the poor themselves, for accepting 'free' money.
To me, a finance ignoramus, the real questions are:
a) How did a few million bad loans bring down such a huge system?
b) How did the system get so much debt?
The answer to a) seems simple. While the government could have paid the $500 billion or so in bad loans, or Wall Street could have given up bonuses for a couple of years, the way that the debt was securitized meant that each bad dollar in investment was multiplied by factors in the hundreds. All on paper, of course.
As for b), I note that Robert Rubin states that 'this could not have been foreseen'. I can only attribute this to a quasi-religious belief in the magic of the market. Several people that I know were worried at the trends over 15 years ago. Nominal house prices were rising faster than inflation and incomes combined, and too many people were using their homes as cash machines by re-mortgaging.
This fiat money was magnified many times by the system through derivatives, until we reach the current state. With a world's annual production of goods and services at about $55 trillion, there is an estimated $1000 trillion in derivatives. That is, we have mortgaged everything on the Earth for the next 18-19 years. That's what I call a sub-prime loan!
Homeopathic 'medicines' are made by diluting active chemicals with distilled water until no molecule of the ingredient is left. We appear to be actively approaching homeopathic wealth, diluted by paper.