I came across this article on Cognitive decline: the irreducible legacy of open borders reading the comments on a post by Captain Capitalism on the same issue with the provocative title: Who Will Pay for Everything When the White People are Gone?
Whatever you might see as the cause, there is no doubt that wealth generation in an environment of personal and political freedom was first achieved by the culture of the North Atlantic, and it is these economies that have continued to succeed where others have not. The template is there for anyone to adopt, and has been in Japan, Singapore, Taiwan and a scattered few others. But it is the North Atlantic tribes and their diaspora who have done far better than the rest. Here is the core of the message found in the first article:
A country’s economic success is causally connected to the intelligence of its people; that a nation of dimwits cannot compete with a nation of philosophers; and that between the simpleton and the savant lies a distribution of intellect that differs among peoples. Immigration from the third world will move the center of gravity of brainpower down the IQ spectrum, and in the long run, through influx, fecundity and gene flow, will have a lasting effect.
The basis of all this is described as “smart fraction theory”.
The fundamental assertion of smart fraction theory is that per capita GDP is proportional to the size of a country’s smart fraction, a proposition established empirically in The Smart Fraction Theory of IQ and the Wealth of Nations and also in Smart Fraction Theory II: Why Asians Lag, where it was determined that a verbal IQ of about 106 sets the lower bound of the smart fraction.
The rest is math along with the four laws outlined. There to be read at the link along with the article by Captain Capitalism who provides his own projections of what this will mean for living standards as time goes by. We have been living through a Golden Age.