I think you should read Marx's Capital. It is devoted to answering that question: the generation of surplus value and its consequences in society. As you suggest, such system is not stable, explaining capitalism's tendency to crisis.
You could probably map this out.
If X is the united states, and Y is another country. All of the money in business/laborers would eventually go to the top (business) because of the "profit" or 2x but then how does the worker not end up in debt. Unless the worker did the same thing you know building services that multiplied their worth instead of hourly rate, even hourly rate though if you had high wage.
I don't know I tried reading Adam Smith's Wealth of Nations man that was a hard book to read.