This means getting as much as they possibly can out of its employees while paying them as little as possible.
Jonathan H, I can identify with much of what you say. I copied the sentence above to say that, where I live, this is exactly wha bosses believe. And it has resulted in a very serious problem, namely that employees don't feel it's in their interest to protect the company's interests, that they have no real intention to do quality work, and that they leave as soon as possible.
I feel this is the stupid entrepreneur's creed.
Let me give you an example of what I mean. Once, I had to buy ink for my printer. I went to this store, and the person who came to talk to me said they had none, but she knew where I could find exactly what I wanted. Without my even asking, she put a small piece of paper in my hand and left. It was the phone number of the competition. What this person was doing was to refer all the customers to the competition. It's not that they didn't have any ink cartridges; it is that the owner was not there to make sure his salespeople actually sold items. The competition had bribed the company's salespeople in a very clever way.
One way they have stretched this belief that economic rationality is the same as squeezing the poor is that, in some companies, there is no way you will get a job if you're older than 30. As a seller of services that I am, it is easy for me to see that they don't value experience. They just want a monkey there, who will take peanuts. Younger people don't have children and will accept lower salaries. That is not "economic rationality" but unfair advantage.
I don't think "economic rationality" necessarily means "firing employees". I wonder how many of us would rather pay the fee involved in talking to a real person instead of having to navigate endless phone menu options. "Thank you for calling XYZ, where we're great and you know it because we say so".
We have to distinguish "economic rationality" from "maximizing my profits no matter what". Of course the boss who fires you wants to have a justification.
In Spain they failed not because they hired more people, but because they made stuff they would never use. Like airports no one uses. And, in general, because they lived beyond their means. Of course, what your "means" exactly are is the heart of the matter.