Contributions of Samuelson and Nash
The paper
Fishburn, Peter C. & Peter P. Wakker (1995)
“The Invention of the Independence Condition for Preferences,”
Management Science 41, 1130-1144
discusses the invention of the independence condition. Here is some background on the topic, assigning priorities to Nash and Samuelson.
- Priority of Samuelson on the general concept of separability in consumer choice.
Savage's sure-thing principle and the independence condition of decision under risk are close relatives.
- Shared priority of Nash (1950) with Marschak (1950) on the axiomatization of expected utility (introducing the independence condition).
The paper
Bleichrodt, Han, Chen Li, Ivan Moscati, & Peter P. Wakker (2016) “Nash Was a First to Axiomatize Expected Utility” Theory and Decision 81, 309-312,
discusses the independent invention of the independence condition by Nash (1950), simultaneously and independently from Marschak. Here is background material to document this independent discovery.