> The US' population is much more diverse than European countries
Having lived in both continents I can tell you this is absolutely not true, particularly in Western Europe.
Large Western European cities/capitals are usually a huge melting pot of locals, foreign Europeans, North Africans, Sub-Saharan Africans, Middle Easterners, Central Americans, South Americans, South Asians and East Asians.
Cities like Amsterdam and London are even white-minority, highlighting how multicultural Europe can be.
Go to some of the largest German cities and you'll feel like you're at a UN meeting.
> I think it's likely we are leaving a subsection of our population behind economically and this is showing up in the population numbers.
Well, this is unfortunately a human problem and I'm not entirely sure if there's a solution or if it could be mitigated. I like UBI as a concept and I do think it would be enormously beneficial for humanity as a whole, but I'm not sure if it's feasible.
The point about diversity is absolutely true. Notwithstanding London, Britain is still 75% British Germany is still 86% German. No ethnic group in the US make up more than 20% of America. And even if you treat “white” as a meaningful category, that makes Britain (at 80%), one of Europe's most diverse countries, as white as states Americans regard as very white, like Massachusetts. Germany is up there with Wisconsin or North Dakota.
UBI as a concept sounds nice on the surface, but it's second order effects lead to inflation and economy is mostly back to where it was, just with higher prices. It's been played out multiple times as govts hand out stimulus money.
UBI is easy - give people money. It solves demand problem, but not the supply problem.
I'm a much bigger fan of UBS i.e "Universal basic supply". Every legal citizen gets a minimum of supply for food, shelter, healthcare, education, water, electricity, transport. That requires innovation production and supply chain of goods and services.
The supply problem is solved by people wanting more than the basics. Most people would rather have more than just the bare minimum guaranteed by the UBI.
Farmers, construction workers, nurses, teachers, etc. will have more money to spend than people who don't want to do anything at all. They'll be able to afford things that we already know are desirable: travel, entertainment, more diverse foods, etc.
Government should not have to coordinate production of most of those things. Ordinary supply and demand should handle it. UBI just puts a thumb on the scale: it ensures that the "demand" for the basics of life is matched by the economist's understanding of demand (measured in money). That avoids the mismatch of people who have infinite desire for food (because they're starving) but no money (because they cannot work), without having to make arbitrary decisions about who is too disabled to work.
The resulting balance of labor will be very different from now, to be sure. Some people will choose not to work entirely, though probably fewer than you might expect. Some jobs that are currently low paid because they require low skills will increase in cost because they're unpleasant. That strikes me as fair: we need people to clean toilets and it's not a good thing that it's the lowest-paid job.
That will cause other jobs to decrease in salary to compensate. Probably us computer programmers, to start with, along with movie stars and CEOs and other people who basically get to suck up all of the available cash in the system for somehow being uniquely desirable.
I'm utopianizing here, and I don't mean to oversimplify what will undoubtedly be a very complex and different kind of economy. But my point is that plain old capitalism accounts for those "second order effects" to ensure that supply exists for the basics. Even though people's basic needs are met, there is plenty of indication that actual people want more stuff and are willing to work for it.
Unless an economy produces more physical goods and services, adding more money simply inflates the prices.
UBI is a feel good measure with bad second order economic measures. The idea works only if paired with policies that legit increase supply of goods that people want.
For $1000/month, one has to guarantee the quantity and quality of basket of goods are still available to everyone.
If you give a 100 million $1000/month, so a million of them can travel, gotta produce more planes, airports and people working on those airports for the million to effectively travel.
To see inflation gone wrong, look at Venezuela and Zimbabwe.
Price doesn't matter. It's just a number. This is about distribution.
Inflation reduces the value of those who already have cash. That is the point of UBI. It says that everyone should have enough to live on. The wealth has to come from somewhere. Inflation takes it from those who have a lot. The actual numbers adjust to match.
The OP's question was whether it would affect supply. And it will, but not as much as they think. Most people will continue to work anyway. But their relative salaries will be different.
You can google "X white minority", I recall reading some papers on it when I was going down an immigrant assimilation research rabbit hole (I'm an immigrant so it's a topic that fascinates me).
https://bamproject.eu lists some cities along with data (e.g: Malmo, Amsterdam, etc).
Having lived in both continents I can tell you this is absolutely not true, particularly in Western Europe.
Large Western European cities/capitals are usually a huge melting pot of locals, foreign Europeans, North Africans, Sub-Saharan Africans, Middle Easterners, Central Americans, South Americans, South Asians and East Asians.
Cities like Amsterdam and London are even white-minority, highlighting how multicultural Europe can be.
Go to some of the largest German cities and you'll feel like you're at a UN meeting.
> I think it's likely we are leaving a subsection of our population behind economically and this is showing up in the population numbers.
Well, this is unfortunately a human problem and I'm not entirely sure if there's a solution or if it could be mitigated. I like UBI as a concept and I do think it would be enormously beneficial for humanity as a whole, but I'm not sure if it's feasible.