> there is little reason to believe they cannot exist at previous population levels with some adjustments There is all the reason to believe that. In the past

> there is little reason to believe they cannot exist at previous population levels with some adjustments There is all the reason to believe that. In the past few years, Japan took in a record number of immigrants, and yet they still werent able to stop the population decline. They lost ~600,000 people/year in total or during that time period, if i remember right. 'Some adjustments' wont fix that. A total overhaul of the society is necessary.