AMP Capital chief economist Shane Oliver said with lockdowns growing in spread and length, the hit to GDP in the September quarter could be as much as 2.5 per cent. That would be about $17 billion in lost economic activity.

He said the Greater Sydney lockdown was costing about $1 billion a week while the various lockdowns across Victoria had cost at least $5 billion. Unemployment, now at 4.9 per cent, could reach 5.5 per cent with most of that increase in NSW.

“The extension of the Victorian lockdown for another week, the long Sydney lockdown and various shorter lockdowns in other states and regions is amplifying the economic hit to the current quarter,” Dr Oliver said.

“We’re certainly looking at a hit in the September quarter, a large one, but depending on when lockdowns come to an end then we should see a bounce in December.”

Dr Oliver also cautioned the June quarter was at risk of also showing negative growth, given some lockdowns occurred in June.

But he said while there was a financial cost from the lockdowns, they had delivered a major health benefit.

“We’ve avoided 48,000 deaths on a per capita basis compared to what’s gone on in other countries, so you have to keep all of this in perspective,” he said.

NAB chief economist Alan Oster said the bank’s customer data showed the recent lockdowns were knocking key parts of the economy, including those areas not directly affected by health orders.

He said over the past two months of lockdowns, there had been a slowdown of household consumption, which is down by 3 per cent since the start of the year. By contrast, in 2019 consumption was up by 20 per cent over the same period.