Homo Economicus
Etymology
A mock-Latin coinage meaning “economic man,” which arose in the late 19th century largely among critics of John Stuart Mill’s portrait of the self-interested economic actor. It echoes Xenophon’s “Oeconomicus”; the Latin “oeconomia” traces to Greek “oikonomia,” household management. The term has always carried a faintly ironic, critical edge.
noun phrase · /HOH-moh ek-uh-NOM-ih-kus/
The idealized model of a human as a perfectly rational, self-interested agent who consistently maximizes their own gain.
What it names
The simplifying fiction at the heart of classical economics — useful for building models, and useful as a target when you want to point out that real people are nothing like it.
Example
The whole pension design assumed a homo economicus who reads every disclosure and never procrastinates.
Related idea
The counterweight is bounded rationality, which keeps the idea of a reasoning agent but replaces perfect optimization with real limits on information, time, and mental capacity.