I'd thought that this was reflected in some university departmental organisation, with M.I.T. being the one that came to mind. Despite there being a behavioural economics section there, though, so far as I'm aware Economics remains its own department.
Kahneman's training and primary focus were both in psychology, but he was awarded the somewhat problematic Nobel Memorial Prize in Economic Sciences. Multi-discipliniarity is in fact A Thing.
Princeton bio:
Daniel Kahneman is Professor of Psychology and Public Affairs Emeritus at the Princeton School of Public and International Affairs.... He has been the recipient of many awards, among them the Distinguished Scientific Contribution Award of the American Psychological Association (1982) and the Grawemeyer Prize (2002), both jointly with Amos Tversky, the Warren Medal of the Society of Experimental Psychologists (1995), the Hilgard Award for Career Contributions to General Psychology (1995), the Nobel Prize in Economic Sciences (2002), the Lifetime Contribution Award of the American Psychological Association (2007), and the Presidential Medal of Freedom (2013).
The counterargument to the proposition in my earlier post would be to show that there is economic activity which relies on nonhuman behaviours. Automated financial trading or AI-based management systems (financial, corporate, industrial, governmental, etc.) might be possible exceptions, which raises further interesting questions.
Though there is certainly daylight: my subfields of Industrial Organization and Computational eocnomics are way more related to quantitative finance, ML, and similar than voting behavior.
The thrust of my pithy question was whether or not the principle subjects of economics --- of human production, consumption, and exchange --- where the sum total of all psychological inquiry.
I suspect not.
The relevant questions are:
1. Which field of study encompasses more elements, economics or psychology?
2. Are these fields intersecting, and if so, is one a proper subset of the other or not?
In a Venn diagram sense, how do the sets relate?
Psychology includes numerous branches, fields, divisions, and foci, of which choice determination is only a very small element. See for example:
<https://www.simplypsychology.org/branches-of-psychology.html>
<https://en.wikipedia.org/wiki/Psychology#Major_schools_of_th...> (specifically schools of thought).
Contrast branches of economics. Numerous, but ... somewhat less expansive as compared with psychology:
<https://en.wikipedia.org/wiki/Outline_of_economics#Branches_...>
Note that psychology, economics, sociology, political science, and anthropology all emerged out of what had previously been moral philsophy largely during the 19th century. Divisions and focus are somewhat arbitrary and strongly influenced by institutions and other pressures --- in the case of economics, political policy influences are notoriously strong, though other disciplines aren't immune from same. But if I had to matryoshka the two, I'd nest econ within psych.
<https://duckduckgo.com/?t=ftsa&q=psychology+of+groups>
<https://opened.tesu.edu/introsocialpsychology/chapter/the-ps...>
<https://scholar.google.com/scholar?q=psychology%20of%20group...>
There's also the fact that the economics profession, and the Economics Nobel committee, have both been making pains to include a broader set of dynamics under their scope. Among the more notably economic polymaths prior to Kahneman was Herbert A. Simon, possibly better known to the HN crowd for his pioneering work in AI and computer science, though he also worked in economics and, again, psychology. He was awarded the 1967 Nobel in economics on decision-making in the context of bounded rationality.