This really isn't a one-dimensional question with an easy "studies have shown" answer. For a start, it would require a definition for what "benefits host countries" means -- benefits tax receipts? Proportion willing to volunteer for the army? Benefits eployers of low/high-wage labor? Number of companies founded? Strength of the literary tradition?

That said, the most obvious parallel here is the indians expelled from Uganda [1], who were essentially the merchant class of that country. And I believe have done very well in England.

[1] https://en.wikipedia.org/wiki/Expulsion_of_Asians_from_Ugand