Some economists have revised down their 2011 GDP growth forecast in the light of the 0.6% fourth-quarter fall. This is questionable. To the extent that last quarter's decline was due to December's bad weather, the effect will be to shift production from 2010 to 2011, resulting in faster growth this year.

The Office for National Statistics estimates that the weather effect reduced GDP by 0.5% in the fourth quarter. This implies a negative impact of 0.125% for the year as a whole. Assume that two-thirds of the production shortfall is recouped in 2011, with the remaining third representing a permanent loss. The net effect would be to boost annual growth between 2010 and 2011 by 0.2 percentage points (offset by a 0.125 point reduction to 2010 expansion).

The economists, presumably, are revising down their 2011 growth forecast because underlying GDP performance was supposedly weak last quarter, with this negative surprise outweighing the positive arithmetical impact of the weather disruption. The view here remains that the ONS estimate of a 0.1% fall in weather-adjusted GDP is too pessimistic – either the 0.6% headline decline will be revised up or the negative weather impact was significantly larger than assumed.

Job vacancies are typically a good coincident indicator of GDP. The Monster index of online job postings rose to a new post-recession high in January, suggesting a solid underlying economic recovery – see first chart. (Confirming the improvement in labour demand, the Reed job index – more timely but with a shorter history than the Monster index – surged in February.) An indicator based on changes in claimant-count unemployment gives a similar message – second chart.

Monthly GDP rose by 3.6% in February and March 2010 following a snow-related 1.5% drop in January. A similar or larger rebound is likely following December's 2.0% decline, implying first-quarter GDP growth of more than 1% (assuming no upgrade to the current fourth-quarter estimate). With monetary trends looking more promising, the forecast in a previous post of GDP growth of about 2.5% this year is maintained.

In a speech last June, the MPC's Adam Posen stated that it was "difficult to attribute the rise in inflation in the UK solely or even primarily to "one-off" factors like VAT, past sterling depreciation, or energy prices". Instead, "the most logical and empirically reasonable explanation for inflation creep is some unanchoring of inflation expectations, caused by the series of above target outcomes for UK inflation in recent years".

Such views suggested some common ground with his hawkish MPC colleague Andrew Sentance but Dr Posen has long since moved on. In a speech last week he claimed that, but for sterling depreciation, core inflation excluding indirect taxes and energy "would have been below its long-run trend (that assumed consistent with meeting target headline CPI inflation in the future)". Meanwhile, "long-term inflation expectations ... remain anchored".

Dr Posen changed his policy position in September last year, soon after the US Federal Reserve signalled its intention of launching QE2 asset purchases. In a speech at the end of that month, he called for similar action in the UK, not on the basis of any new data but because "policymakers should not settle for weak growth out of misplaced fear of inflation". He registered his first vote in favour of such a policy at the October MPC meeting.

Dr Posen is a close academic colleague of Fed Chairman Bernanke and shares his view that the post-crisis environment is fundamentally deflationary, echoing Japan in the 1990s and the US and Europe in the 1930s. With this prior, it is hard to conceive of data developments that would persuade him to vote for policy tightening any time soon. Dr Posen, however, may face a dilemma later this spring if, as seems likely, the Fed shifts to neutral and signals no further extension of QE.

Growth in the Bank of England's favoured broad money measure accelerated to an annualised 4.9% in the three months to January – above a level likely to be consistent with achievement of the 2% inflation target over the medium term.

The Bank's Governor, Mervyn King, has repeatedly cited sluggish broad money growth as a reason for nonchalance about the current inflation overshoot. This ignored the possibility that the velocity of circulation of money would rise in response to the negative real interest rates imposed by the Bank – an increase in velocity has the same economic impact as monetary expansion. Velocity has indeed picked up, climbing 2.1% during 2010 – the largest annual rise since 1979.

The February Inflation Report addressed the velocity issue for the first time (see box on p.17), conceding that under current circumstances a given rate of broad money growth could be associated with a faster increase in nominal GDP. Achievement of the inflation target requires nominal GDP to expand by 4.5-5% per annum (assuming a trend real growth rate of 2-2.5%), so this suggests maximum allowable broad money expansion of about 4%. Absent evidence of a slowdown in the recent velocity increase, it would be safer to aim for a lower number.

As well as weakening a key argument of rate rise opponents, faster broad money expansion supports the view that fourth-quarter GDP weakness was erratic and the economy will grow solidly during the first half of 2011. Also encouraging is a strong reacceleration of the narrow measure "non-interest-bearing M1" (comprising currency and traditional current accounts), which often leads domestic spending. NIB M1 surged by 31% annualised in the three months to January.

The pick-up in broad money has been driven by bank lending to the public rather than private sector – banks bought £10.2 billion of gilts in January and £21.6 billion in the latest three months, adding 5.6% to annualised broad money growth. Bank purchases compensated for foreign gilt sales of £1.5 billion in January – the largest outflow since April 2009.