From what I've heard part of it is also a "business culture and expectations" type of issue. As that's vague/broad, I'll try to illustrate what I mean by that with two imaginary orders (I used house in this example as I know there's a lot of "house buyers" that operate like this - they don't specify much detail, yet even if you don't specify detail, you have certain expectations of what you get for your money):
- Order(1) a "house with furniture", delivered and set up in location y with maintenance budget z/yr.
- Nothing else than the above is specified.
- Order is made to 500 different people per country/theoreticized "business culture"
- Now repeat the same order but this time set a max budget x+inflation adjustment +allowance, based on the median of the lowest price quartile of which of the houses from the previous order(1) met your quality criteria. This is Order(2).
If there is a "business culture and expectations" type of thing in play (affecting quality), one should see a statistically significant skew in the "delivered to budget furnitured houses"-quality* that persists if the test is repeated.
If my theory is correct, "furnitured houses made to budget" from some countries would rate consistently lower.
Why? Well I would imagine that that higher % of the people taking this contract from the lower rating country/culture would have "business cultural" reason driving their approach to the project/contract that gets them immediately to a worse start: eg. they might not do thorough investigation and research at the target/delivery site - eg. perhaps as "test buyers" had intentionally chosen a site that is not suitable for building - such as on top of toxic waste dump. I've investigated why it is that schools and houses built by government cronies always end up near these waste dumps. If the "business culture and expectations" were "best they can" the seller would take into account their brand, image, pride and deliver the house to alternate location or demand cleaning up the toxic waste first. If the culture was "worst" then the probability of the builder building straight on the dump would be higher.
* About quality rating: If quality metrics are unknown, a comparison methodology could be developed by studying/measuring/feeling-sensing differences of the houses delivered. (this was to avoid going into details of what makes a high quality house and how to deal with ranking unknowns)