[coffeemug]

In practice third world countries are very unproductive, and it's immediately visible to the naked eye. Many shops and restaurants have half a dozen people (or more!) taking the order and handling the check, there are entire extended families manning market stalls that barely sell anything, cabbies just hang out all day waiting for a ride, etc. You might be theoretically right, but I think that's not actually how it works out in reality.

[epolanski]

I have made a very specific example, you extrapolated some other data from it.

If you want a clearer comparison take Japan and tell me their average driver, nurse, teacher, policeman, factory worker, carpenter, painter, car mechanic, shop assistant, barista, bank clerk, etc does "less" or "less efficiently" than his american counter part.

Because there is a huge difference in measured productivity between them.

There might be, at times, some added productivity in US due to having more capital at disposal to adopt some technology, there might be some other benefits from being more risk prone in US? Sure. But that amounts for smallish differences and sure not for the immense gap measured by economic measures, which, at the end of the day, as explained with the initial sleeping nurse example is still $/hour.