Since you asked so nicely. Here's a source that seems to be reviewing the various studies on it.
https://migrationobservatory.ox.ac....s/the-fiscal-impact-of-immigration-in-the-uk/
Of course since it's a detailed and scientific review of the data it's of **** all use on this board and will now be ignored.
As it's over a year old, it would of been pooh-poohed if it didn't fit with the narrative
And it's "have", ffs