[4death4]

The actual 0th law of economics is the law of decreasing marginal utility. You can't expect specialization and productivity to increase indefinitely as density increases. Clearly, we're at an inflection point. How can people specialize and be productive if they can't even afford a place to live?

[JumpCrisscross]

The actual zeroth law would be a corollary of the second law of thermodynamics: scarcity.

> Clearly, we're at an inflection point

This has been claimed repeatedly throughout history. Without knowledge of the future, it is impossible to know whether we are at an inflection local or global. With resepct to any American city, we know we are far from the inflection point because we have counterexamples abroad.

[4death4]

> With resepct to any American city, we know we are far from the inflection point because we have counterexamples abroad.

Such as? There are very few places in the world that match the productivity of the U.S. I don't think Luxembourg counts as a counterexample, for instance (population 640K). Singapore, maybe, but its population is under 5.5 million.