In this lecture, Prof. Shapiro revisits the psychology of distributive politics that he had introduced in lecture 5 to walk the audience through the logic of absolute versus relative gains, Loss Aversion, Endowment effect, and Prospect Theory. He uses these concepts to help us better understand the evolution and importance of unions in the US and Europe, Left and Center Parties and distributive politics in two-party versus multiparty systems, questioning the idea that multiparty systems are more redistributive in today’s world.