Abstraction

Underneath the taxonomy, every economic system is an answer to one question: how do strangers cooperate at a scale far beyond the number of people they can personally know and trust?

Traditional economies solve it by keeping the group small enough that everyone does know each other. Command economies solve it by putting one authority above everyone. Markets solve it by making trust in the counterparty unnecessary — you trust the contract and the courts instead. Each answer has a different breaking point, which is why they fail in such different ways, and why the sequence in history reads as one solution outgrowing its scale and handing off to the next.

The practical consequence, for anyone modelling markets: the system is a regime, and regimes change what the data means. A price under price controls, employment where most work is informal, GDP where the state directs credit — each measures something different from its namesake elsewhere. Models trained across a regime boundary quietly average incompatible quantities, and that is one of the more common and least examined ways applied financial models fail.