Perhaps it was your use of “economic” — if you meant “efficient” it would have been a better word to use. An economic model would be mathematical by definition.
Similarly, Lean (with a capital L) doesn’t mean “without fat” — it is a rich philosophy that espouses much more than reduction based on cost.
And I accuse you of misrepresenting the conclusions of the article because you have. The article says 1. it did find evidence of test-first delivering less complex, highly tested code and 2. that it *didn’t* find evidence of improved cohesion and lowered coupling. That doesn’t mean the latter is not true — simply that it couldn’t be proved. Your sentence preceding the link is “There is some empirical evidence that suggests Test Driven Development (TDD) *does not* improve code quality (such as coupling or cohesion metrics).”
How do I know what you think? By the way you have structured your argument. I’d happily provide counter arguments but first we have to deal with the inconsistencies in yours.