Short-handed this Christmas? Here's one reason.

Australia's been experiencing a shortage of migrants lately, as businesses across all the states will attest as they struggle to replace that now-inaccessible talent pool. But it's not just that people have stopped arriving. They've been leaving as well, and with borders still opening and closing like a revolving door, they haven't come back.

According to the latest data from the Bureau of Statistics, there was actually a net loss of 88,800 people from the national population within the last year - June 2020 to June 2021 - with migration tumbling across every state and territory.

"Contrast this to 2018-19, prior to the pandemic, when the country recorded a net gain of 241,300 people," said ABS Director of Migration Statistics, Jenny Dobak. "In the decade prior to the pandemic, there was an annual net gain from overseas migration for each state and territory. However in 2020-21, during the pandemic, there was a decline in net overseas migration in every state and territory."

ABS figures show that the largest decreases in resident population came from the group aged 20-29 - the population of young working adults, including students upon whom many businesses rely for casual labour and temporary staffing.

The partial border reopening, which went ahead this week despite Omicron worries, might reverse the decrease - but slowly. Meanwhile, businesses will have to put up with the ongoing labour shortage. But there's still a silver lining: Australia's TFR, while low, is still within replacement levels, with births continuing to outnumber deaths despite the pandemic, and the workforce is ageing more slowly than expected in previous years.