To me, it seems obvious that every financially successful (through merit or otherwise) and well educated person you can draw into your country, the better. If such a person makes your country home, the likely-hood of them contributing to the economy is high.
Despite this, emigrating to the US from Western Europe is extremely arduous. Either you are transferred via a multinational facing high competition for the place or you enter the lottery alongside others who won't necessarily contribute as much as you are able to.
The incentive for a nation such as the US seems perfectly apparent from the outside. Grab the best and brightest from countries with excellent education and similar cultural backgrounds in exchange for citizenship. When there is so much demand, why not? Seems to only be a win.
I cannot help but think that western nations have entered some sort of pact (as many SV companies did) in regards to non poaching. Each country wants to keep their best, so some agreement (formal or otherwise) is reached to prevent mass exodus to one.
The left wants to maximize multiculturalism. This has become a sort of fundamental value to that tribe (rather than a means to an end), and their fundamental anti-value is racism/xenophobia/intolerance of anyone not white-Christian. So that tribe will resist any hint of an attempt to selectively immigrating people from culturally or racially similar countries, because such immigration actually threatens to reduce multiculturalism, which to them is a fundamentally evil thing. So they'd call it racist.
In addition, even just choosing people for wealth or intelligence or English skills, you'd end up with a big cultural/racial skew towards white people (compared to the world population), so the left would call it racist for the same reasons.
Those on the right might be happy with such immigration, but it's too difficult of an argument to make and it's too easy for the left to call them racists if they suggest anything like it. So as a proxy, they tend to argue for reducing all immigration.
I must be missing a lot of the details but I think it's some sort of political compromise/deadlock like this.
You can reverse engineer the government's motivation by looking at the policies it seeks to introduce and asking your self what worldview would motivate such policies. There's a nice little ML project.
Democrats like all immigration, refuse to go ahead with high skill only immigration reform unless republican compromise
The end result is deadlock.
I'm a Democrat. I don't like all immigration. With some quibbles, I'm mostly behind long existing rules barring certain “bad people” from immigrating.
OTOH, I think hard caps are bad ways of dealing with the social costs of high quantities of immigration of people that aren't excluded, and it would be better to assess direct fees for people who wanted to immigrate beyond the caps (or without a preference category but who aren't personally barred for bad conduct, etc.) And it would be better, in existing preference categories with caps, to align allocation per-country with demand (or just abandon specific per-country allocations altogether and just a use a global limits) so we don't have a handful of countries with very long waits for legal immigration in various categories due to per country, rather than in-total, caps.
I also have issues with the priorities (both positive and negative) implicit in some bits of the existing structure of immigrant and non-immigrant visa categories, but that's kind of secondary.
Well, that will surely make america bigly again.
It's about supply and demand.
If you supply labor at X skill level, an influx of immigrants at X skill level (but not of Y or Z skill level) will reduce the buying power of your wages.
Taking it to real life - people tend to oppose immigration when they are at X skill level, and support it when they are at Y or Z skill level. It's raw self-interest often dressed up as altruism or principle.
You can see this understanding here whenever H1B is discussed - suddenly supply and demand becomes an obvious economic concept.
And often they're in they're twenties, meaning society didn't have to pay for the expensive first two decades of growing up. Basically a live is 8 decades, 4 decades of which are unproductive, and 4 decades are productive. If you get an immigrant, you get a 6 decades person that's unproductive for only 2 decades -- and some other society paid for those 2 other unproductive decades.
Median age for all Americans is 36.
Sources:
http://www.migrationpolicy.org/article/frequently-requested-...
http://www.pewhispanic.org/2015/09/28/chapter-5-u-s-foreign-...
And indeed, when you remove most of the population who are younger than twenty, the medium age of the group overall will increase.
Sheesh! Next thing you know you'll be asking to price petroleum in something other than USD or something!
There are numerous countries that fit this profile. The majority of Central/Eastern Europe, few Asian and South American countries, even with Africa having some. Instead, they expect for people from developed countries go through the nightmare of getting a visa, being screened and then live in places like Cali where cost of living is ridiculous. US could easily give out 1 Mil easy-to-get visas with easy-to-get transition program to a green card that would bump their economy, instead, they are creating walls everywhere.