Economic imperialism

In the past half century economists have invaded other social science disciplines, bringing advanced techniques and original ideas. Long-suffering academics in those fields have complained of economic imperialism. Famous examples include the family (Gary Becker), crime (Becker again), race (OK, this is really just "Becker imperialism") and politics (James Buchanan and Gordon Tullock, Mancur Olson)*.

Delacroix - Attila the Hun

It is a cliche that conquerors end up being changed by the conquered. When reading economics papers, I now find that papers which bring a uniquely "economic" approach to bear on a broader social science problem are greatly outnumbered by  papers where an interesting idea from the other social sciences motivates a new analysis in economics. The analysis is often formalized using game theory, and/or tested using econometrics, but that does not mean it uses an "economic approach" with a focus on material incentives and trade-offs. This is a subtle shift, not a discontinuous changeover. Famous examples: reciprocity (Fehr and Gaechter, influenced by Gouldner), social networks (Jackson, influenced by Granovetter), identity (Akerlof & Kranton, influenced by Tajfel).

Kublai Khan

When did this changeover happen, and what does it mean for the future of the disciplines?

* but also William Riker, a political scientist. Uniquely, political scientists imperialized themselves.