Immigration does not help if the migrants refuse to work or don't have the skills required. Many source cultures sequester their women, so straight away half the potential is lost.
A stable working age population is probably more important than a stable population per se, and in countries with an ageing workforce, that cohort will presumably shrink faster than the population <80.
Yes, if the working population is stable, that's key, as is the ratio to the older non-working-age population. Basically, you need more working-age people than retired people, preferably by a factor of 2 or 3.
Immigration does not help if the migrants refuse to work or don't have the skills required. Many source cultures sequester their women, so straight away half the potential is lost.
A stable working age population is probably more important than a stable population per se, and in countries with an ageing workforce, that cohort will presumably shrink faster than the population <80.
Yes, if the working population is stable, that's key, as is the ratio to the older non-working-age population. Basically, you need more working-age people than retired people, preferably by a factor of 2 or 3.