The housing 'bears' are again out in force, says Douglas McWilliams, Chief Executive of the centre for economics and business research (cebr) in their 'forecasting eye'. "But don't bet your home on a house price collapse," he says.

McWilliams says that previous doom and gloom forecasts may have lost people money had they taken 'doom and gloom' biased advice in 2002. For instance, the average homeowner who sold his house following Roger Bootle's forecast in the Daily Mail, far from making money, would have missed out on £30,000 of house price appreciation by March this year.

Getting into his stride about the bears being out in force again, Douglas McWilliams says the so-called Dr Doom, Tony Dye, was quoted by the BBC on 14 April as saying that London house prices would fall by 30% over the next 5 years. City firm Durlacher issued a report 'Bubble Trouble' in February 2004, saying that a housing market crash would be 'very messy'. Mr Bootle is repeating his forecasts from two years ago.

Even the cebr have been predicting that house price inflation would level off temporarily this year - which certainly has not happened yet unless one believes the government's index (which their assessment suggests to be flawed).

The doomsters are right to point out that there are definite signs of overheating in the housing market. And it is certainly true that house prices are high in relation to incomes by historic standards. But equally, there are major signs of housing shortages in a large number of areas and - as the Barker review confirmed - new build construction is moving far too slowly to offset not only future shortages but even to make inroads into current shortages.

Meanwhile, although mortgage interest rates are set to rise, they are likely to rise from a level which is very low by historic standards and these low interest rates have made housing much more affordable by historic standards.

Because there are economic influences in different directions it is critically important that economists weigh together all the facts when trying to understand likely house price movements.

cebr's 'housing futures' model, is they believe, the most comprehensive model of UK house price movements available taking account of population, planning restrictions, new build, demographic changes, movements in household size, costs of building and regional migration as well as interest rates and household incomes (among other factors). The 'housing futures' model is currently estimating that house prices are within 2% of their equilibrium level - in other words prices are about right, given the UK's unusual housing situation.

If prices continue to shoot ahead, they will ultimately have to fall back (but from the new higher levels). Cebr's best estimate is that there will be a soft landing, with house price inflation decelerating as interest rates rise and affect affordability.

A collapse could happen but its chances are well below 50% and even if it did happen would start from higher price levels than we have today. Anyone tempted to act on the basis of the house price bears should remember how much would have been lost by those who believed the doommongers in 2002.

Today, the risks of losses are less but - taking into account the cost of moving which for a property worth just above £250,000 is over £14,000 - the arguments are still against selling up and moving for purely economic reasons.