Federal Treasury calculations released to economic modellers yesterday suggest that the average Australian lost an inflation-adjusted $26,400 in 2008 — 11.8 per cent of their real wealth.

"This quantifies the collateral damage from the global slump," said CommSec economist Savanth Sebastian, who used Treasury data to come up with the 11.8 per cent figure.

"It's the biggest fall in records going back 48 years," he said.

"It's the only time wealth has fallen for four continuous quarters."

The average Australian's real estate, sharemarket and financial wealth amounted to $223,985 in December, down from around $250,000 a year earlier.

The Treasury does not break down the estimate into individual components.

The collapse comes at the end of a decade in which wealth per Australian roughly doubled.

Mr Sebastian said it was possible that wealth had began climbing again since the December quarter: "Household prices improved in the early months of the year and the sharemarket jumped sharply in March."

Separately released Residex data showed house price growth in every city but Perth (down 3.9 per cent) in the first three months of the year, with Melbourne prices up 0.5 per cent over the three months and 1.6 per cent in March.

The Westpac-Melbourne Institute leading index deteriorated further in February, pointing to a bleak economic outlook as the Government frames the May budget.

The index is made up of indicators thought to point to economic conditions three to nine months ahead, including overtime worked, manufacturing material prices and the nation's productivity.

It is now running at an annualised rate of minus 5 per cent, well below its long-term average of plus 3 per cent.

"The rate of deterioration of the index is truly remarkable," said Westpac chief economist Bill Evans.

"The consistent run of negative reads is comparable with Australia's previous recessions, which began in 1961, 1974, 1982, and 1990.

"A comparison with the last recession is disturbing. During that recession the annualised growth rate of the index reached a low point of minus 3.4 per cent. In this cycle we are already at minus 5.1 per cent.

"We are forecasting that the economy will bottom in 2009. The current rapid deterioration in the index points to downside risk for that forecast."