HES: RE: QUERY--Origins of Homo economicus?

[Forstater, Mathew]

This will partly depend on whether you are interested in first/early
English-language usage.  I believe you may find the earliest usages in
German and Italian, and probably from the mid-19th century, if not
earlier.  Pareto, certainly (Manuale di economia politica, 1906).  You
might want to check out (but not for an answer to your question):

Joseph Persky, "Retrospectives: The Ethology of Homo Economicus,"
Journal of Economic Perspectives, Vol. 9, No. 2. (Spring, 1995), pp.
221-231.

Mathew Forstater