BBC trotts out the old nonsense about immigrants solving the dependency problem.

See here.

I'm sick the back teeth (as are others) of pointing out that young immigrants are not a long term solution to the dependency problem. (That’s the fact that the population is aging, thus the pensioner to “people of working age” ratio is rising.) Reason is stark staring obvious: young immigrants themselves eventually grow old.

And anyone who doesn't understand that needs to take an IQ enhancing pill.

In fact several studies have been done into exactly what happens if a country relies on young immigrants to keep it’s dependency ratio constant: the result is a catastrophic rise in the population – something like the population doubling every thirty years or so.

Moreover, with the spread of 21st century medical knowledge, drugs etc to less developed countries, those countries will also have a dependency problem in about twenty years time.

And to add insult to injury, it’s very questionable as to how serious the dependency problem really is. That is, increases in output per head comfortably exceed the rate at which the dependency ratio is deteriorating. Thus while that deterioration obviously means a decline in living standards ALL ELSE EQUAL, the reality is that “all else” is not “equal”. 

That is, the deteriorating dependency ratio hinders the rise in living standards A BIT. But it does not stymie it anywhere near totally and completely.