[antillean]

Apart from what merpnderp said about per capita income, I'd guess there are at least two important things at work here.

The first is that the disparities between regions within a country like the US are quite different from the disparities between countries across the world. In particular, wealthy regions and cities in rich countries tend to have lots of poor people. I think they might even have disproportionate shares of the poor.

Then there's the redistributive effects of things like having a single currency, single regulatory regimes, and explicit central government redistributive taxation. These all (especially the last) work to prevent disparities between regions within rich countries from becoming as big as disparities between countries across the world.

[ux-app]

> "The first is that the disparities between regions within a country like the US are quite different from the disparities between countries across the world."

That's a fair point, I'm sure there are differences which make looking at a country in isolation not very useful.

What about the EU? There is free travel across the EU and the economic disparity between member states is huge. For example look at UK/Germany as compared to Estonia/Bulgaria.

This hasn't resulted in catastrophic mass migration across the union.

[antillean]

The European jury is out on whether or not there is ongoing catastrophic mass migration across the EU.

Anti-immigration sentiment has been surging in the EU over the last few years in large part because of perceptions of excessive migration from eastern European countries like Estonia and Bulgaria ("the periphery", as they call them) to western and northern European countries like the UK and Germany ("the core countries", as they call themselves). In the UK, for instance, the UK Independence Party got something like 13% of the popular vote (though only 1 seat, because as bad as UKIP is, the first-past-the-post electoral system in modern Britain is worse) in this year's general election, and they're a single-issue, anti-European-immigration party. Word is that similar things are happening in other rich European countries, as seen with the National Front in France, the Danish People's Party in Denmark, and the AfD in Germany.[1]

To zoom in a bit on the UK (where I live), there is evidence that migration from the EU is high and growing[2][3]. But I don't think that anyone outside of those who are right-of-mainstream on this issue think it's catastrophically high. I'd guess at three main reasons for that. Firstly, accession to the EU requires certain "convergence criteria", which include levels of economic prosperity and social stability which, while not strict enough to mean that all the joining countries are virtually the same on these things, are strict enough to mean that they aren't as far apart as, say, the US and Haiti -- or even the US and Mexico. Secondly, the EU has a good few common institutions, including ones that do things along the lines of redistributive taxation.[4] And thirdly, there are differences in language and culture which might be restrictions to many people, especially in a continent as linguistically (if not culturally) diverse as Europe. (I'm guessing that and size are parts of why everyone isn't flocking to Luxembourg.)

1. Germany's Angela Merkel under threat from Pegida rallies -- http://www.cnbc.com/2015/01/06/threat-to-merkel-from-right-w...

2. British and other EU migration -- http://www.migrationobservatory.ox.ac.uk/britains-70-million...

3. Bulgarian and Romanian migration to the UK -- http://www.ons.gov.uk/ons/rel/migration1/migration-statistic...

4. EU contractors and beneficiaries of funding from the EU budget -- http://ec.europa.eu/contracts_grants/beneficiaries_en.htm

[ux-app]

Thanks for your European perspective. I live in Southern Australia, so about as far away from Europe as possible, so all of my knowledge on the issue is anecdotal.

In the EU, hasn't the net result (across Europe) been a positive one? I.e. the positive impacts on weaker economies have outweighed the negative impacts on the more developed, core, countries?

I think you're absolutely right that the difference between US and Haiti can't really be compared with the differences between EU member states.

I really hope the EU experiment does end up working. A world without borders would be amazing.

[antillean]

Yeah, I think -- and just about everything I've seen on it says -- that the net effect of the EU has been positive for all European countries and most European people involved.

I also hope the experiment works, and not just because I'm a migrant to Europe who's annoyed at needing visas to work and, in some cases, even just visit! The European project's going through a bit of a rough patch now, though, with Greece and the rise of anti-immigration sentiment. I think it needs serious reform to work and be good.