Church Next for the Muslamic Kids?, page-122

Its been known for a very long time - the declining
"fertility rate" in western countries.

A complex situation, which is based on the fact that higher incomes have a correlation with declining birthrate.
Some of it partially due to self actualisation - the ultimate point in Maslow's hierarchy.
Maybe it is partially due to selfishness but that is a matter for discussion as within self actualisation.
Obviously, lower socio-economic, lesser developed countries have a high birthrate due to a requirement to maintain and sustain the family - or so it has explained by demographers.
China's contemporary history is a glaring example of the higher income lower birthrate correlation albeit with additional impetus from the Mastery/ Bastardry? of the CCP.

I'll leave you to consider the Baby Bonus return v. importing nationalities with baby factory mentalities and propensity to accumulate benefits?

One thing is clear,
contrary to what many outline is a global problem
too many people,
too much resource utilisation,
too much greenhouse gas,
the overriding concept for governments (often comprised of bleating greenhouse gas and global warming freaks)
increased population growth to drive for economic growth is their internal mantra.
Your idea of deportation has considerable merit - currently.
Pity that there are too many imported to begin with - we could have saved ourselves the trouble.