All that's needed is that new immigrants should do significantly better than they did in their home country, do some good in the country they've moved to.
Notice that your two assumptions nearly contradict each other. After all if the average citizen of the old country was as capable of doing good as the average citizen of the destination, the old country wouldn't be the kind of place one needs to leave to do significantly better.
That argument seems to me non-responsive, fallacious, or at least inadequately fleshed out, in three different ways.
Immigrants needn't be representative of their country of origin, in which case arguments about the average citizen in that country of origin aren't automatically relevant.
The "average citizen of the old country" needn't be "as capable of doing good as the average citizen of the destination" for NancyLebovitz's point to go through; they just need to generate a net gain (however one operationalizes "a net gain") at the margin.
Something like a fallacy of composition: a priori, "the average citizen of the old country [being] as capable of doing good as the average citizen of the destination" doesn't automatically imply that "the old country [isn't] the kind of place one needs to leave to do significantly better". Given, say, increasing returns to scale & specialization, it's quite possible that denizens of a tiny country would be outperformed by those of a bigger country, but would nonetheless be quite capable of matching their new neighbours if they moved to that bigger country.
That argument seems to me non-responsive, fallacious, or at least inadequately fleshed out, in three different ways.
Yes, it was a Baysian not a mathematical argument.
Immigrants needn't be representative of their country of origin, in which case arguments about the average citizen in that country of origin aren't automatically relevant.
They are unless you have reason to believe the immigrants are above average.
Given, say, increasing returns to scale
Comparing per-capita GDP with populations suggests we have decreasing returns to scale.
One way to s...
If it's worth saying, but not worth its own post (even in Discussion), then it goes here.
Notes for future OT posters:
1. Please add the 'open_thread' tag.
2. Check if there is an active Open Thread before posting a new one. (Immediately before; refresh the list-of-threads page before posting.)
3. Open Threads should be posted in Discussion, and not Main.
4. Open Threads should start on Monday, and end on Sunday.