The Washington Post has long been a megaphone for increased immigration, but it seems even more so under the ownership of Amazon’s Jeff Bezos. The July 18 edition of the paper was peppered with pro-immigration opinion and analysis with the centerpiece an article on how the economy depends on mass immigration.

The core argument – asserted by economists polled by the WaPo – is that the economy can grow only on the basis of a rising population or greater productivity. The U.S. birth rate, though still higher than most other developed nations, has declined in recent years (despite the fast rising number of births to the foreign-born) and the retiree age group is increasing. With current productivity gains low, the need, according to these economists, is to artificially increase the population by immigration.

Of course the countries that have the fastest growing populations do not necessarily have fastest rising economies. Of  the two billion plus population countries, India has a much faster growing population than China, but the latter has a GDP nearly five times larger. Some economists will admit that the human capital of the immigrants matter, and that more educated immigrants offer a greater contribution to the economy than those who are poorly educated.

The economic argument for mass immigration also tends to ignore the demographic fact that immigrants age just like the native-born, and compensating for their eventual departure from the workforce by admitting still more immigrants is a form of Ponzi scheme that commits the United States to a never-ending and rapid population expansion at the same time that public concern about its impact on natural resources and the environment would argue in favor of slower population growth.

What is lacking from most of the discussion of immigration and the economy is the increasing mechanization of our society that may obviate the long-term need for more labor. The United States has mechanized much of its agricultural industry, especially for grains, but also in harvesting other seasonal crops. And, we now have machines milking cows. But still, the U.S, lags in mechanization behind other countries, like Israel, that have a limited supply of seasonal workers. The potential for economic growth through mechanization far outweighs that which can be achieved by importing more workers. But the availability of low-wage workers defers the need to invest in expensive machinery.

The advantage of focusing more on mechanization is that the resulting increase in GDP (Gross Domestic Product) is also an increase in GDP per capita, whereas if the GDP increase results from a larger population size, the per capita growth may be lost or at least muted for the average worker.