Paul Krugman estimates Brexit would cost two percent of GDP, all other things remaining equal. But all other things won't remain equal.
In the long run, any Western country that continues to import several hundred thousand to several million nonwhites per year can expect massive GDP declines due to exponentially increasing anti-white mayhem and bigotry.
Nonwhites devote themselves to free riding in Western countries. Increasing nonwhite political power results in economic Marxism coexisting with or dominating capitalism. Put simply, nonwhites pursue rent seeking almost anyway they can get away with, whether by the dole, affirmative action, Wall Streeting, ethnoracial networking or dozens of other methods. As free riding increases, whites increasingly adopt self-destructive ideologies, especially Hitlerism, African values, and Southwest Asian values.
As the West already found out, it doesn't take a plurality of individuals of Southwest Asian descent to cause totalitarianism.
Racial diversity makes most individuals of most races worse than they would otherwise have been.
Genetic engineering might not save matters if, as expected, nonwhites engineer their children eugenically for IQ but dysgenically for even more egoism, familism, and ethnoracial nepotism. Many individuals underestimate the dangers of high IQ, low character individuals. Studies finding high IQ Ivy Leaguers to be more ethical are junk science. The studies use unrepresentative sampling, faulty measures of character, and participants smart enough to self-promote by seeing through the study design. The historical evidence of mass destruction caused by the Ivy League's "best and brightest" far outweighs the junk science. Levels of economic and industrial espionage by nonwhites will continue to escalate.
Brexit still leaves cultural Marxism in charge. But at least Brexit is a tiny first step toward taking control from global totalitarianism.
What's one difference between a libertarian multiculturalist and a man wearing a tinfoil hat? The man with the tinfoil hat in more likely to be moved by evidence.
Women are inclined to seek signs of commitment. But are taught in hedonistic cultures to seek superficial signs of commitment. Thus, empty words and ethically worthless pieces of carbon are given more value than more practical gifts. Buying a woman a stroller would be a major faux pas.
Men from societies with few eugenic forces seek control over female fertility by rape, seduction games, and de facto slavery.
A major part of the multicultural war to demoralize the West is getting white men and women to have no accurate self-respect, making us easier to take advantage of.
Happy Father's Day.