I am slightly confused as to what the difference between Subgame Perfect Equilibrium and Subgame Perfect Nash Equilibrium is.
I was told there is a difference, but now I found many lecture notes that use the terms as substitutes.
Thank you!
$\endgroup$ 31 Answer
$\begingroup$The two terms, SPE and SPNE, refer to exactly the same equilibrium concept in game theory, i.e. a strategy profile that induces a NE in every subgame.
On Wikipedia:
$\endgroup$In game theory, a subgame perfect equilibrium (or subgame perfect Nash equilibrium) is a refinement of a Nash equilibrium used in dynamic games. A strategy profile is a subgame perfect equilibrium if it represents a Nash equilibrium of every subgame of the original game.
