A newborn baby is also an unskilled, uneducated individual that wouldn't be able to speak the local language without months/years of language learning. Presumab

A newborn baby is also an unskilled, uneducated individual that wouldn't be able to speak the local language without months/years of language learning. Presumably there is a net benefit in this case. I think there is a net good to some unskilled immigration - say 1% of the population each year. But I'm willing to be proven wrong. Is there some objective measure we can agree on which approximates 'net benefit'? For example, if total tax paid by these migrants over their lifetime is more than total welfare payments, would that indicate a net benefit?