CML analysis shows that, after the previous stamp duty concession that ended in December 2009, the spike in sales of exempted properties that had pre-empted the end of the concession was matched by a corresponding slump.
HM Revenue & Customs is due to publish an impact assessment of the current concession this autumn, but the CML believes that its withdrawal could distort the pattern of monthly transactions in a similar way to the ending of the previous concession.
This would be unhelpful, given the fragile state of market confidence.
The CML believes that there continues to be a good case for fundamental reform of the "slab" structure of residential stamp duty, and has long advocated a move to a marginal rate system similar to income tax. But this is a longer term objective, and less pressing than the need to avoid short-term negative effects by removing the first-time buyer concession.
The concession itself is likely to be costing the government only a modest sum in foregone revenue as a result of the relatively low number of transactions in the market at present - and it was, in any event, a stated intention (albeit by the previous government) that the cost of the concession would be offset by the new permanent 5% higher rate of stamp duty on properties worth more than £1 million, which took effect at the start of the current financial year.
The lion's share of residential stamp duty yield - 87% - comes from sales of properties of more than £250,000 value. In absolute terms, the revenue from stamp duty has fallen markedly from a peak of £6.7billion in 2007-8 to just over £4 billion in 2010-11, but it would rise only modestly if the concession is allowed to expire as planned, since low transaction numbers are the primary reason for the decline according to the CML.
CML director general Paul Smee commented: "While there is no clear evidence that the stamp duty concession has incentivised an increasing number of first-time buyers to buy, it is highly likely that there would have been fewer of them if it had not been in place.
“The CML believes it would be a mistake to pull the plug on the concession - at least until the housing market returns to a firmer footing.
"First-time buyers need to get the message that the government supports them as they take their first steps into a housing market where confidence needs to be restored.
“The housing market can act as a force for growth in the economy, but if this is to happen then buyers, lenders and builders alike all need a clear message that the government sees them less as part of the economic problem, than as part of the economic solution."
