(Image: Museums Australia)

Tucked away in Budget Paper 3 today will be a crucial number for the government's economic growth estimates and for Scott Morrison's self-declared target of 3.75% GDP growth every year for five years.

That's where the budget forecasts for population growth -- fertility and net overseas migration -- will be tucked away.

Last year, long before anyone had heard of COVID-19, the government used a dodgy population figure to inflate its economic growth forecasts for a pre-election budget: the fertility of Australian women was forecast to surge from 1.781 babies per woman in 2018 to 1.9 in 2021 -- a remarkably rapid demographic turnaround for our declining fertility rate.