All that really matters at the G20, at 1026GMT
What can we tell in advance about the G20 communique?
1. Any figure placed on the fiscal stimulus will refer to what's been achieved already: between $2trn and $3trn. Any new commitment will be a surprise.
2. Expect $500bn extra for the IMF and $100bn specifically to free up trade finance.
3. Lots of fine words about the poor countries and probably some money.
What are the variables?
I would scrutinise the wording in two areas: monetary policy and regulation. We will see today whether the ECB moves further towards zero interest rates and whether it signals what it will do when conventional monetary policy runs out. If quantitative easing gets enshrined as an offically recommended tool by the G20 it will have gone from outlaw/pariah status to the ruling centre of power in less than 90 days.
On regulation, there is still the potential for this to cause a bust up. I would caution against the idea that it is done and dusted. The British media did not fully translate the Merkel-Sarkozy press conference yesterday. I was there and I read it as a very detailed list of red lines on hedge funds, bonuses, tax havens and securitised finance.
I think it will be very hard for the Franco-German bloc to achieve what they want on securitisation: they want effectively to abolish off-balance sheet finance in principle - with all instruments traceable back to a regulated onshore bank.
However, in return for a climbdown on this I think we'll get stronger language on hedge funds and tax havens than the Anglo-Saxons want. In particular with tax havens Sarkozy made clear he is not fetishising issuing the blacklist now, but when it is issued, he wants decisive action to close them down - not only as tax boltholes but as screens for off-balance sheet finance.
If the final shape of the communique is what I think it's going to be, then it's Obama who has to go home and explain to Wall Street how he's going to implement it. They will not be happy.
Finally I think, despite all the cynicism, we have to give plaudits where they are due: if the G20 manages to go from insignificant to a body where the big economies can horse trade effectively and then implement the results, that's an achievement. The summit too could be seen as an achievement. Certainly, compared to the charade of Washington G20, where people simply read out statements and left, it seems to be a working body.
Will it be enough to head off a slump? If you buy the slump scenario, no. The fiscal stimulus lacking co-ordination and inadequate (compared to the 3% of GDP asked for by for example Paul Krugman) will not stave off the collapse. The re-regulation could accelerate the retreat to national pools of capital. And trade finance does not reignite the multi-step production process: that's an issue of credit, not trade finance.
The IMF money will probably be enough to stop collapse in East Europe. But then the stricken countries simply settled down into snowy stasis. And, since aid to the poorest countries has not exactly ignited an industrial revolution there, more aid will do what it always does.
That's my prediction: scrappy, inadequate, half-successful but not a disaster, indeed a personal success for Gordon Brown. Let's see...