Zero-sum thinking on immigration will make America poorer
The authors are making the very popular claim that the "lump of labor fallacy" and that migration is not "zero-sum" conclusively demonstrate that any permissive migration scheme is undoubtedly beneficial for everyone in any country at any time ("In short, immigration creates more economic opportunities for everyone: a win-win scenario").It is true that there isn't a "lump of labor" (the amount of work is not fixed) and that migration isn't "zero-sum" (where each participant's gain or loss of utility is exactly balanced by the losses or gains of the utility of the other participants).But those are very narrow claims. It doesn't follow every conceivable permissive migration scheme is beneficial for every receiving country and it certainly doesn't follow that nobody is harmed by any permissive migration scheme.The H1B scheme, a topical example here, is restricted to a small number of professions by statute (and in practice is 70% software people) so the arguments about migration generally and the economy broadly shouldn't be applied without further consideration.It is easy to imagine if you had a profession that has some limitation to demand and narrowly allowed migration for that profession only that given a sufficient number of migrants you would displace some current residents from the profession and preclude some number of current residents from joining that profession and lower salaries of the profession.