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).
