Cheap money stimulates demand. More demand encourages supply. So far, so very simple. But how quickly and how adequately extra demand is met on the supply side, or whether it spills over instead into price inflation, depends on real-world dynamics. Apply such principles to UK government policy in the housing market – where stimulus has come from increasingly generous FirstBuy, NewBuy and now Help to Buy programmes – and the conclusions are far from reassuring.

The first two schemes assisted in anything from 15 to 30 per cent of unit sales at volume housebuilders last year. But on a rolling 12-month basis, private sector housing starts were still down 8 per cent year on year in the final quarter of 2012, with completions up 3 per cent. Perhaps the best that could be said was that the private sector showed some pick-up in the latter half of 2012, and looked slightly less dismal than the market overall. Total annual housing starts fell 11 per cent in 2012, to under 100,000, woefully short of estimated needs.

Still, that leaves housebuilders cheering the latest policy ratchet from their rooftops. Investors should join them. The HTB scheme, started in April, requires no financial commitment on the builder’s part, and is accessible by a broad swath of buyers. Barratt Developments said on Thursday that HTB had contributed 400 reservations over five weeks, a significant uptick from the earlier incentives. Its private order book is 30 per cent higher than a year ago at ￡1bn. With debt reducing and the share of houses built from older, low-margin land falling, the market re-rating has been striking.