The reason people want to move to the US is the US's culture. The people share a wide agreement for rule of law, want to resolve issues through the political process, can usually be shamed into supporting freedom of speech, and don't want to kill their neighbors for having the wrong religion.
It's not something magical about the soil that makes people want to move to the US. It's the culture. The more people that can use it, the better, but add too many new people too fast and it suddenly stops working.
> The reason people want to move to the US is the US's culture.
No dude, it's the money.
I have at least a dozen friends who are on H1Bs working in SV for different large software companies. They're either going there because that's where the best-paying jobs are or they're staying for just a couple of years to save some money.
If you were to beam all the Americans into space and them beam all the Mexicans into their place, they wouldn't magically achieve US levels of income just because of their physical location.
The culture doesn't enable the money. Historical reasons going far beyond that explain it very well, among them: the size of the internal American market, the amount and ease of investing capital within the US, leverage of the US government's global projection of power by its industries, ease of immigration (prior to this past decade's immense increase in difficulty for migrating legally for skilled migrants), etc etc.
It's true that just swapping people places right now would not substitute anything. But you can bet that the immense natural resources, available land and influx of immigrants through the 20th century have impacts as much, if not more, important than whatever contemporary cultural trends exist.
Natural resources don't guarantee success; conversely, lack of natural resources does not guarantee doom. Russia and Brazil on the one hand, and Japan and Britain on the other hand, tiny island nations, relatively speaking.
Culture has a lot to do with it. Brazil had the immigrants (and still does have LatAm immigrants). On the other hand Japan has been very averse to immigration.
Why do you think North Africans move to Europe and South Americans move to the US? Because it's the closest country with the best economic opportunities.
Economic immigration is huge. Cultural immigration is tiny.
In fact American culture is the joke of the world (its media can be consumed from wherever and is quite popular, but its values and policies on things like health care, sexual education, religion, crime etc are mocked by more than a few modern economies) and its institutions (e.g. ensuring freedom of speech, freedom of the press, gender equality, life expectancy, racism, gay rights) usually don't find themselves ranked among the top 20, let alone top 10 of countries.
In fact, it's one of the main reasons I wouldn't want to move to the US. I'm in the Netherlands, my partner is American, we could move anytime. But I much prefer the politics, institutions and culture here. (and it's far from perfect here).
I mean you write 'share a wide agreement for rule of law, want to resolve issues through the political process, can usually be shamed into supporting freedom of speech, and don't want to kill their neighbors for having the wrong religion' as if the US is unique in this regard. You write it as if the poorest people on the planet simply want to move to a country that 'doesn't kill its neighbours for having the right religion', as if this is the nr 1 thing on their mind, if only they could move to such a country! That's ridiculous, as opposed to wanting to move to the US for economic opportunities to get a decent standard of life for them and their family.
It's absolutely not the culture and legal/political process. And occasionally Americans do seem to kill their neighbours for having the wrong religion or skin colour.
It's almost entirely money/opportunity. That drives everything.
It's not something magical about the soil that makes people want to move to the US. It's the culture. The more people that can use it, the better, but add too many new people too fast and it suddenly stops working.