First, even if someone actually paid the 300k it takes to raise a child, that doesn't mean that person owns the adult.
And second, who is paying that? Education (in Japan and the UK) is primarily funded at a national level. So Tokyo/London, have already contributed significantly to the cost of that person's education (and to the education of plenty of people who will never move there to work). And most of the costs of raising kids are paid either by parents or at a national level.
It seems to me this is just post hoc justification for taking resources out of productive areas that need them and sending them to unproductive areas that don't. That might be "democratic" if there are a lot of unproductive areas. But it isn't fair or efficient or effective. And it will soak up resources better spent helping people who actually need them...
First, even if someone actually paid the 300k it takes to raise a child, that doesn't mean that person owns the adult.
And second, who is paying that? Education (in Japan and the UK) is primarily funded at a national level. So Tokyo/London, have already contributed significantly to the cost of that person's education (and to the education of plenty of people who will never move there to work). And most of the costs of raising kids are paid either by parents or at a national level.
It seems to me this is just post hoc justification for taking resources out of productive areas that need them and sending them to unproductive areas that don't. That might be "democratic" if there are a lot of unproductive areas. But it isn't fair or efficient or effective. And it will soak up resources better spent helping people who actually need them...