We propose that individuals consider future versions of themselves to truly be separate persons, not simply as a convenient modeling device but in terms of actual brain systems and decision-making processes. Intertemporal choices are thus quite literally strategic interactions between multiple...

In economic situations a player often has preferences regarding not only his or her own outcome but also regarding what happens to fellow players, concerns that are entirely apart from any strategic considerations. While this can be modeled directly by simply writing down a player's final...