The number of people working more than one job rose by 17.5 per cent in the September quarter, new data shows.
But the number of casual employees in Australia was still down on pre-pandemic levels, the data, released by the Australian Bureau of Statistics, showed.
The number of people working more than one job grew by more than 100,000 to about 732,000 people, which was still down on pre-pandemic employment levels.
There were 2.3 million casual workers in August, about 22 per cent of employees across Australia. In May, the proportion of casuals had fallen to 20.6 per cent, the lowest rate since August 1991.
The bureau's labour statistics head Bjorn Jarvis said the recovery in secondary jobs had been a key contributor to the 1.7 per cent overall jump in filled jobs between the June and September quarters.
Professor Phil Lewis, the director of the Centre for Labour Market Research at the University of Canberra, said as service sector industries reopened from shutdowns, there was a burst of demand in part-time jobs.
"When we say those service sectors have recovered, I mean that's not strictly speaking true. They've gone from shut down to actually running business but those businesses certainly aren't at full capacity now. When they're not at full capacity, it means they don't need to employ people for as many hours as they did before," he said.
Professor Lewis said it was not yet clear whether businesses have adapted to reduced staff hours or whether staffing requirements would need to be increased once the pandemic further subsides after successful vaccines are widely distributed.
"What we do know is in a lot of cafes, restaurants, etc, they're increasingly making use of family labour rather than hired labour. And so, of course, those people don't appear in the statistics," Professor Lewis told the Sunday Canberra Times.
Professor Lewis said for students and young people who needed part-time work, long-term reduced hours would be a negative outcome from the pandemic.
"The big worry for them is will these hours recover or not? We would hope they would because we would hope businesses will get back to normal and they will have full capacity, but currently that's not the case. We know a lot of businesses are still struggling," he said.