Every set of hands comes with a mouth also. Immigrants increase the supply of labor but also the demand for what labor produces.
Perhaps the confusion arises because the immigrant does not necessarily purchase goods and services produced in their new country. We all work in a global economy were its impossible to follow all of the transactions between what we produce and what we consume. That would be true even if nothing ever crossed international borders.
You're implicitly assuming that production is "hand-bound". It could also be bounded by natural resources.
For example even if the number of mouths to feed increases, the number of farmers cannot increase beyond what there is farmland for. So the hands will be competing for who gets to plough the fields, in exchange for a meal. Too many hands along with too little land, and the losers starve.
Not only that, but...humans are humans right? What makes human A more entitled than human B just because they were born in the right country? What we really need is global wealth redistribution (e.g. more foreign aid).
And, it is not necessary that we would just raise salaries without cheaper labor available through immigration. Many jobs at the lower end would simply be automated or a service might disappear altogether (e.g. gardeners are a luxury, too expensive you just do it yourself).
I hope someday we'll be able to think more globally, maybe we can in a future post scarcity economy.
From a purely economic perspective immigrants capture almost all net economic boost for themselves. Capital/property owners get a small boost. It's a wash or net negative for the general population of the country.
That's from a purely economic perspective. What nobody ever wants to discuss is that creating an ever-more culturally and ethnically fractious country is a huge problem looking ahead decades quite aside from near term GNP prints.
Did you just say that immigration is harmful because workers get most of the benefit and property owners relatively little? This economic perspective seems to be only looking at the economy of one group of people.
An immigration policy should be crafted to serve the needs of the citizenry. Is this controversial? If you're an open borders nutjob, let me know and I'll allow you to carry on in peace.
Perhaps the confusion arises because the immigrant does not necessarily purchase goods and services produced in their new country. We all work in a global economy were its impossible to follow all of the transactions between what we produce and what we consume. That would be true even if nothing ever crossed international borders.