But perhaps more important than when to exit is the question of how and whether indeed it will be so easy and simple for central banks to simply wind down the supply of medicine. In the context of the ECB for example, I remain rather sceptical.

However, this day is all about the Fed decision  and although I only rarely delve into account of US monetary policy decisions (comparative advantage you know!) this one is important since it was always going to be parsed very closely for signs of hawkishness on rates on the one side as well as indications of the future wind down of asset purchases. Now, for those who expected a big bang, I have to side with Macro Man that it seems to be much ado about nothing in the sense that the Fed basically reiterated the general view that although economic activity had been showing positive signs lately and especially in the context of leading indicators pointing to a strong bounce in Q3 and Q4 activity, the fundamentals of very low capacity utilisation and deleveraging across the real economy remain intact. In the context of Fed speak this translates into maintaining the current rate target at the zero bound and the the forward looking statement that rates are to kept low for an extended period; 

Conditions in financial markets have improved further, and activity in the housing sector has increased.  Household spending seems to be stabilizing, but remains constrained by ongoing job losses, sluggish income growth, lower housing wealth, and tight credit.  Businesses are still cutting back on fixed investment and staffing, though at a slower pace; they continue to make progress in bringing inventory stocks into better alignment with sales.  Although economic activity is likely to remain weak for a time, the Committee anticipates that policy actions to stabilize financial markets and institutions, fiscal and monetary stimulus, and market forces will support a strengthening of economic growth and a gradual return to higher levels of resource utilization in a context of price stability.

With substantial resource slack likely to continue to dampen cost pressures and with longer-term inflation expectations stable, the Committee expects that inflation will remain subdued for some time.

In these circumstances, the Federal Reserve will continue to employ a wide range of tools to promote economic recovery and to preserve price stability.  The Committee will maintain the target range for the federal funds rate at 0 to 1/4 percent and continues to anticipate that economic conditions are likely to warrant exceptionally low levels of the federal funds rate for an extended period.

So far so good then and this was really all we needed, one would imagine, to extent the rally in risky assets as well as the downward trend in the USD as the new funding currency for carry traders and others of their ilk. So far, there has been no signs of panic anywhere and everything seems to be all engines go.

Meanwhile, the Fed did actually give away some details as to how the future bout of asset purchases are to be conducted. On the matter of treasury purchases the Fed will its total purchase of $300 billion by the end of October. Most of us would naturally like to be able to predict what this will to do yields and prices and really you could spin this two ways. In the context of supply side worries, the Fed's withdrawal from the treasury market should push down yields if we add the, perhaps dubious assumption, that the $300 billion worth of supply of treasury bills has only been there to the extent that the Fed has been the main bidder (Say's law and everything). On the other hand it could also push up yields in a world where one assumes that there has been a decisive need to issue such bills and now that the Fed is stepping aside new buyers must step in and notwithstanding those with a printing press of their own, it should push up yields. Although this may seem quite innocuous and technical (i.e. unimportant) it may turn out to be important in a general context when it comes to the ability of economies (not just the US) to lift themselves out of the mire without the crutches of stimulus to lean on.

In the context of the Fed's outright asset purchases, the statement delivered good news for bulls/doves in so far as goes the fact that although the Fed was invariably going to issue a deadline, it seems to have been pushed somewhat out in the distance; well, at least a quarter. Consequently, the Fed will buy $1.25 trillion of agency mortgage-backed securities and up to $200 billion of agency debt, purchases which are set to be concluded by the end of the first quarter and not by year end which was the final date I had been led to believe judged by the points made in various economics report digested over the last week.

So, it is here perhaps that we may be looking at a disappearing bid in the context of the Fed gradually but surely reducing its presence in the market for MBS turds not to mention the agency market which went belly up as Fannie and Freddie crashed and burned. In the nice soothing light of efficient markets it is difficult to expect the decision to wind down purchases to be a big market mover as long as the incoming bout of data continues to provide plenty of upside and no downside. But if we get a setback just around the time when the Fed had envisioned to stand down its most aggressive measures of QE, one finds it difficult not to expect general sentiment and thus, in a forward looking perspective, real economic activity to take a hit which is exactly what we would all like to avoid; the double dip recession or "WL" recession if you will.

Ultimately, it is of course all still a great big mess, something which was neatly conveyed by the way Bloomberg handled the message carried by the IMF envoy to the G20 summit. On the one hand, the IMF was quoted for urging central banks to map a viable and transparent exit strategy and on the other hand Managing Director Dominique Strauss-Kahn was quoting for urging policy makers to not withdraw fiscal stimulus to quickly. Lost in translation are we?

Well, I am perhaps being unfair here to the editors of Bloomberg not to mention the IMF in particular since ultimately; talking about exit strategies is not the same thing as enforcing them. However, I do feel rather strongly about the need to make the following point that the two are of course intimately connected and withdrawing QE cannot but affect the trajectory of fiscal stimulus. This is a point which I believe for example is absolutely crucial to understand in the context of the Eurozone where the ECB's refinancing operations seem to be implicitly underpinning national governments' efforts to shore up their capsized economies.

In this context and assuming that both the BOJ and the ECB will be trailing the Fed somewhat, it will be most interesting to see whether Bernanke manages withdraw the bid on financial markets currently offered by the Fed's policies and indeed whether others may follow in his footsteps and withdraw theirs.