I always believed it was a matter of time before the US Fed (and probably the UK's Bank of England) dusted off its voluminous cheque books and engaged in further bout of Quantitative Easing (QE) by writing gargantuan cheques pumping more money into ailing economies.

Last week's statement from the Fed's monetary committee saying it "is prepared to provide additional accommodation if needed to support the economic recovery" suggests that time is close by.

The Chairman Ben Bernanke prepared the ground at the end of August. At the central bankers' get-together in Jackson Hole, he said "the FOMC [Federal Open Market Committee] will do all that it can to ensure the continuation of the economic recovery. Should further action prove necessary policy options are available to provide additional stimulus."

So the question is what will cause them to take action?

Big hints

The Fed and Bernanke have already given some pretty big hints and set out the ground rules. At its 10th August meeting the FOMC said it would consider more stimulus "if the outlook were to weaken appreciably further." So, has the US economy "weakened appreciably" or "deteriorated significantly?" That is the crucial question.

Looking at the latest economic data, an argument can be made either way. For instance, Friday's Durable goods numbers showed the strongest rise in five months, yet the headline number still fell because of weak transportation data.

Corporate spending is still up. Corporate profits remain high. But — and this is probably the most telling number — unemployment remains stubborn at 9.6 per cent and last week's US weekly jobless claims data continued to rise, disturbingly so for this stage of the recovery.

Midterm elections

In deciding when to turn on the QE tap, the Fed also probably had politics on its mind. The closer the date to the congressional midterm elections, the less likely that any real movement would be made. So, the decision of the FOMC to telegraph their intent last week was politically astute.

This was its last meeting before the voting on November 2. Any dramatic action by the fed, such as reintroducing QE would have been pounced on by Republicans as evidence that Obama's economic policy had failed.

So cleverly, the Fed told the markets that they were getting ready but at the same time they didn't give the politicians a brick with which to beat each other senseless.

Ironically, the next FOMC result will be announced on November 3, 24 hours after the midterm polls have closed when no questions of political ingenuity will be needed. My guess is either then, or in December, the Fed will turn on the taps again. Get your umbrella ready, QE is about to rain down.

Tune in to CNN International each weekday at 2200 UAE time to catch Richard's show, Quest Means Business.