When people say to me they are confused about what is happening in the economy, I am not surprised. For weeks the talk has been of the recession ending and the possible start of recovery.

Then along comes the Office for National Statistics with an eye-catching set of data revisions and we are apparently back mired in the sharpest downturn on record (the ONS’s quarterly gross domestic product records go back to the mid-1950s) and the biggest quarterly drop in GDP since the second quarter of 1958.

The key point is that last week’s figures, which were published on June 30 (the end of the second quarter) were a revised estimate of what happened in the first quarter.

The first three months of the year are not exactly ancient history but they came ahead of data and surveys suggesting the economy had begun to stabilise. So the scary “slump” headlines on the back of the ONS’s third guess at first quarter GDP were consistent with the recovery headlines that came with the following day’s purchasing managers’ index, which suggested Britain’s troubled manufacturing sector is close to the end of its recession.

As an aside, older readers may be surprised to learn that 1958 saw a bigger quarterly fall in GDP than the 2.4% plunge we have just had. This was the post-war golden age for the economy, the Harold Macmillan “you’ve never had it so good” era.

It was also, however, the stop-go era, in which one-off falls in GDP were common, though not on that scale. People forget, too, that Macmillan’s immortal phrase, which was actually “most of our people have never had it so good”, uttered in July 1957, was intended to reassure a public far from convinced about his government’s economic management. A sterling crisis in September of that year had to be met with a sharp rise in interest rates. Something must have worked; he was re-elected two years later.

The ONS has reignited the debate about the severity of this recession compared with its predecessors. Any doubt about whether this is worse than the early 1990s has been erased; the peak-to-trough fall in GDP then was a mere 2.5%, only slightly more than in the first three months of this year alone.

Is it worse than the recession of the early 1980s? Then, British manufacturing was more than decimated; it lost a fifth of capacity. The severity of that recession is open to some statistical debate but if you measure the drop in GDP from its peak during 1979 to the 1981 trough, it was 5.9%, compared with 4.9% so far this time. So my view is that this is not as bad yet, though whether it gets that bad depends on the next couple of quarters. Economists are looking for a flattish second quarter, with some even predicting a rise. We will get a first look at the numbers on July 24.

I shall repeat the point about it being impossible to judge how serious this recession is compared with its predecessors until we have been through many data revisions from the Office for National Statistics. At this stage, much of the information about the first quarter remains much more tentative than the precision of the ONS figures suggest. There is a lot of guesswork and modelling in these numbers.

Revisions will not see the recession melt away, but they may make it look different. Take 2005. At the time this was thought to be the year when Britain stopped. Economists believed growth had slumped to 1.5% or less. Now it is 2.2% and rising.

In the last recession of the early 1990s, the Treasury, late in 1992, was working on the assumption that the economy shrank by 2.5% in 1991, slipped by a further 1% in 1992 and would grow 1% in 1993. The figures now for that period are -1.4%, 0.1% and 2.2% respectively.

But we have to work with the material we have now until those future revisions come along. What do the numbers tell us?

Times Recommends

• Lies and cover-up at MG Rover exposed by report
• High oil prices push manufacturing costs up
• Primark founder steps down as chief executive