"We need to have more babies! Our population is declining!"
Well we could subsidize child care.
"Fuck you! Oh whatever shall we do?!"
Well we could provide housing programs for people who want to have children.
"Fuck you! Oh we need to think of something."
Oh, I know, we could subsidize fertility treatments for parents that want children but are having difficulties and can't afford 10s of thousands of uncovered medical expenses at once!
"Fuck you! Oh, woe is me, there's nothing anyone can do!"
Think about it... housing, medical care, transportation. These need to keep up with population growth. If growth is achieved through immigration, then you need infrastructure to support more people. I'm in Canada, immigration has been seen as a positive thing for a long time, but there is a resource squeeze right now and increasing immigration is seen as adding fuel to the fire.
We are trying to address those issues, but it would have been a lot better to put infrastructure in place before aiming to increase the population size.
I don't realy see how it's more expensive to keep a few immigrants alive, who are willing to work and often already have good education, than raising and educating a child for years to come.