Originally Posted by
BadgerBoi
Certainly not an additional 40% of the population, so that's not the reason.
Around 25% of all Australian residents were born overseas.
Over 50% of all Australian residents were either both overseas and/or have at least one parent that was born overseas.
For the US, the first number is closer to 10%. Not sure about the second.
So whilst it doesn't account for the full 40%, it definitely accounts for some of it.