The worst economic slowdown in three-quarters of a century has wiped £40,000 from the wealth of every adult in the United Kingdom, a national total of almost £2 trillion; that is £2,000bn, or £2,000,000,000,000.

The research into the destructive effects of the recession by the accountant PricewaterhouseCoopers for The Independent shows that the fall in the value of property and shares owned by British households between July 2007 and February 2009 has reached the equivalent of 18 months-worth of national output – a colossal destruction that will take many years to recover from and threatens the retirement plans of millions of Britons.

The total value of shares and homes owned by British households has fallen from £6.8trn in 2007 to £4.9trn now – a decline of £1.9trn, or 28 per cent, the PwC figures show.

Download the new Independent Premium app Sharing the full story, not just the headlines

During the credit crunch, houses have lost 20 per cent of their value (or £800bn) and equities 40 per cent (or £1.1trn). Thus, each adult Briton has lost on average £17,000 from the property slump and a further £23,000 in the value of shares, held either directly or indirectly though pension plans. The losses are likely to rise, and there could be a further fall of about 15 to 20 per cent in property values.

John Hawksworth, head of economics at PwC, said: "The knock-on effect of this level of wealth destruction will result in significantly more belt-tightening and reduced spending by households over the next year. The situation could be exacerbated by expected further falls in house prices over the period."

Economists fear that the fall in the value of houses, pension funds and shares will further depress the economy, damaging confidence, reducing spending and prompting more sell-offs in stock markets and by homeowners, risking a vicious cycle of decline and deflation.

The authorities are concerned that the sort of deflation that took hold of the economy in the Great Depression in the 1930s – where prices and output continually fell – could happen again unless the vicious cycle is broken. This week, the Bank of England will inject a further £2bn into the economy, part of its £75bn programme of "quantitative easing", more commonly called printing money.

The PwC analysis suggests that the loss of wealth felt by households and individuals is contributing to the slump in spending in the shops, by about £45bn, or 5 per cent of total spending, relative to what might otherwise have been the case. Traditionally "equity release" from homes and the knowledge that the value of a household's assets are rising strongly, as was seen in the property boom, fuels optimism and consumer spending. But that is being thrown sharply into reverse.

PwC say that the UK's GDP will be 3 per cent lower purely as a result of the credit crunch's destruction of wealth. Mr Hawksworth added: "The estimated loss of wealth of £1.9trn would equate to about £40,000 on average per adult [aged 18+] in the UK, although clearly, these losses will vary considerably across the population."

As recently as last September, the total losses had been limited to £600bn, a serious situation, but moderate compared to the haemorrhaging of wealth since, as stock markets around the world have crashed and banks have been nationalised.

As in previous recessions, the losses and pain from this recession will be unevenly spread. For those fortunate to hold on to their jobs the loss in wealth may be temporary (although lasting years) and notional if they do not have to sell their homes or cash in investments.

But for others, those who lose their jobs and have their homes repossessed and see them disposed of at firesale prices, the recession will mean a 100 per cent loss of personal wealth. On Wednesday, official figures will show that unemployment has climbed above the two million mark, with a peak of more than three million expected by this time next year.