The Jones thesis of cultural transplant devastates the starry-eyed “come one, come all” immigration advocacy popular among progressives and libertarians. It shows that the importation of cultures that are not historically conducive to prosperity is a serious weakness of our current immigration policy. The result could be lower quality governance, decreased trust, less support for free enterprise, reduced innovation, and many other effects large and small. These effects cannot be dismissed with nostalgic references to the Irish of yesteryear.