I think it's a bit odd for the OP to be considering two such different regions as Texas and Catalonia. If you want that Texas lifestyle (big house, air conditioning, car journeys, more evident difference between rich and poor) it certainly mosts much more to have that in a larger, compact European city.
Yes, you make a good point there. The lifestyle in Catalonia/Madrid would indeed be very different from that in Texas. Absolutely that should be a consideration for them.
One thing I noticed though - even though in big cities with good public transport there is no need for a car, it is still seen as a status symbol. You only need to look at the rich/wealthy in Hong Kong, Singapore, London, etc and almost all will have cars not because they need them, but because they are convenient and a signal to everyone that they can afford it. The same with mainland China, you can survive riding a bicycle, but the upper class will not want to do that.
It's the same with houses. All else equal, ownership of a detached house in Hong Kong, London, Singapore, etc., reflects your status in society. It's not something I necessarily support or disagree with, it is what it is.
People can choose to live very simple yet very fulfilling lives and that sometimes is the best for some or even many people. But if you choose a simple life, you can do that easily without an MBA or without moving up the career ladder.
What I am saying is that a lot (but not all) of MBA's, all else being equal, would prefer owning a nice car and nice house versus using public transportation and renting a condo. That may be a generalization, but I have yet to meet an MBA whose goals don't involve one or both of those goals in life. The nature of an MBA attracts people who prefer visible wealth (houses, cars, sending kids to private school) more than the average Joe. As such, an MBA-preferred basket of goods should be the one used to compare cost of living. The Economist article emphasizes that. I am almost 100% sure a lot of prospective international MBA students want an MBA precisely so they will have a better car, better house than the average person in their respective countries (who may be riding bicycles or sharing an apartment with 4 people). If they were satisfied with an average lifestyle, then they would not need the MBA in the first place.