Angus Deaton's Nobel Prize citation mentions his work on consumption, poverty, and this concept, since much of his work deals with how best to measure this concept. Lionel Robbins has criticized Alfred Marshall's attempt to define economics in terms of this concept. Paul Samuelson expanded on Abram Bergson's formulation of a function (*) named after this concept. Amartya Sen argued that the definition of this concept should encompass non-material things, and wrote a book titled after collective choice and this concept. A branch of economics named after this concept is generally said to have two fundamental theorems, including that all competitive equilibria with complete markets are Pareto efficient. For 10 points, 
Angus Deaton's Nobel Prize citation mentions his work on consumption, poverty, and this concept, since much of his work deals with how best to measure this concept. Lionel Robbins has criticized Alfred Marshall's attempt to define economics in terms of this concept. Paul Samuelson expanded on Abram Bergson's formulation of a function (*) named after this concept. Amartya Sen argued that the definition of this concept should encompass non-material things, and wrote a book titled after collective choice and this concept. A branch of economics named after this concept is generally said to have two fundamental theorems, including that all competitive equilibria with complete markets are Pareto efficient. For 10 points, name this term referring to well-being achieved through economic activity.
Angus Deaton's Nobel Prize citation mentions his work on consumption, poverty, and this concept, since much of his work deals with how best to measure this concept.
welfare [accept social welfare] 