It’s a simple proposition. Assets prices are falling so fast, no financier can back them until a loan against them is guaranteed against loss.

What that means is that asset prices have to find a floor. Only then will the real economy find willing partners in the financial economy and finance start to flow.

The question is, when will that happen?

The answer is, no-one knows.

Guesstimates vary from the ridiculously optimistic — the British Treasury forecast — to the ridiculously pessimistic — “never”.

In between, the more realistic: “2012″.

From there we may see a slow growth back to financial and economic health, but it will need a sea-change in regulation and business administration. In particular we need to create bulkheads against the madness of globalized swings that can disrupt the strongest of economies. As David Brook wrote in the New York Times:

“We’re living in an age when a vast excess of capital sloshes around the world fueling cycles of bubble and bust. When the capital floods into a sector or economy, it washes away sober business practices, and habits of discipline and self-denial. Then the money managers panic and it sloshes out, punishing the just and unjust alike.”

As the BBC’s Business Editor, Robert Peston points out: “If you combine consumer, corporate and public sector debt [in the UK], the ratio of our borrowings to our annual economic output is a bit over 300 per cent, or more than £4,000 billion [six trillion dollars].”

Those numbers make even 2012 seem optimistic.

The only safe answer is, “Rebuilding starts when there are no more cliffs to fall off.”