Magnus Spence, director at Spence Johnson, finally has an answer to a question long ignored.

We want to share with you an important statistic that has emerged in an Office for National Statistics (ONS) report issued two weeks ago. No one else seems to have picked it up. 

Hidden away in a 'supplementary table' and surrounded by other useful pensions data, we have been given a first-ever official measurement of the size of the defined contribution (DC) market in the UK. 

Back in 2009, we discovered that there was no reliable measure of the size of the UK DC market. So we had to try to create one. All we had to work with were clues and indicators. 

Our estimate was published in December 2009 in the form of a 'Broad Brush' circular to our friends and clients called "The Gold Rush". We said workplace DC in 2008 was £360bn (€450bn). 

The important thing about our figure was that others who had previously provided estimates seemed to be saying much higher numbers (we have subsequently updated this to £345bn for 2011).  

Since then, we have asked the Pensions Regulator to give us a validated market size. But, for reasons that have never been clear to us, neither the regulator nor any of the other UK government agencies that have an interest in pensions has been minded to reveal the size of the DC market.

Until now. Finally, we have a measure. The value of the assets in the UK DC market at the end of 2010 is £386bn.

For the first time since its inception in the 1980s, the UK DC market has been given a size by the authorities. It is still 'experimental', so, in theory, it could change, but we can probably assume it won't change much.

So the fact the DC market size now exists is very welcome. But doubly welcome is the fact the market is described using the new 'workplace' definition rather than the old 'occupational' one.

You may think this is splitting hairs, but please, believe us, it's not. One definition is useful, the other utterly useless:

Workplace DC = trust based + contract-based pensions (useful)
Occupational pensions = DB + trust-based DC (useless)

We have been campaigning to rid the world of the useless 'occupational' definition for some time, and now it seems this is going to happen, which is great news.

Our push to improve statistics in DC will now shift to another front, or fronts. 

We now want the Pensions Regulator to adopt and use these asset-based numbers in its reports on the DC industry. 

We want the regulator to go further and report on the full workplace DC market - including both trust based and contract-based pensions. 

And we want to be told what the split is between trust based and contract based, since it is clear from the ONS description that this breakdown is available inside its own calculations.

Magnus Spence is director at Spence Johnson