"Don't you think that it would be better to encourage Australians ti have more children "
The greatest incentive would be to make people poorer, but I think that very few people if any at all would subscribe that type of policy.
Birth rate by poverty status in the U.S. 2005-2019 Published by Statista Research Department, Jan 20, 2021
This statistic shows the birth rate by poverty status in the U.S. from 2005 to 2019. In 2019,women in households with an income below the poverty threshold had the highest birth rate at 74 births per 1,000 women.
By the way, the birth rate for Australia in 2020 was 12.561 births per 1,000.
What follows is from the OECD, but before we go there one should note that one thing is the idea that the ideal population size for Australia is in risk of being exceed and another is immigration under a framework where that is not the case. One should also note that is the population size is a problem then any growth including native population growth would be a problem.
The economic impact of migration has been intensively studied but is still often driven by ill-informed perceptions, which, in turn, can lead to public antagonism towards migration.
Labour markets
Migrants accounted for 47% of the increase in the workforce in the United Statesand 70% in Europe over the past ten years. Migrants fill important niches both in fast-growing and declining sectors of the economy. Like the native-born, young migrants are better educated than those nearing retirement. Migrants contribute significantly to labour-market flexibility, notably in Europe. The public purse
Migrants contribute more in taxes and social contributions than they receive in benefits. Labour migrants have the most positive impact on the public purse. Employment is the single biggest determinant of migrants’net fiscal contribution. Economic growth
