It's not though, because the sudden influx of foreign money in a concentrated number of hands causes inflation in the home country, making the cost of living higher for those living there, while the majority are still working lower paying jobs. Not to mention the efficiency loss from the fact they're driving down wages in the host country; so they're losing market value on one end, and then driving inflation on the other (and when prices are higher than the local economy can support it's not efficient).

My ex came from a country that suffered from mass emigration, the place is a complete shit-show and is actually less developed today than it was 30 years ago. Half the buildings are abandoned, most are dilapidated, corruption is everywhere, and now the place is a major drug trafficking hub.

> I don't think that economic parity across nations should be a primary goal of any nation's policy, but I do think it is basically an inevitable, positive side effect of trade.

This should definitely be a goal of anyone who cares about alleviating global poverty and suffering.

> As an aside, I'm also not 100% sure maximum efficiency of human labor across all humanity should be a goal of national policy either, but that is usually what I consider good economics.

There's no such thing as good or bad economics. Economics just describes what is. You can have multiple 'good' or 'bad' policies. It really just depends what you want to optimise for.

Also, maximum efficiency often comes at the cost of driving the price of labour down. If everything was 100% efficient, far less labour would be required than is being used right now, so in the end it comes down to ownership of capital and how things are distributed.