COP 21 recognized the social value of ‘avoided’ carbon emissions. Can this notion be considered as a new conceptual approach of what could be the economic value? In order to move away from the identification of the wealth of a country based on the monetary value of the goods and services produced, the assumption here is that the economic value serves to define the nature of wealth and to measure it. We then emphasize that the notion of economic social value is already present in the works of economists who have developed the notion of social utility and that it is also emerging in discussions about wealth indicators. Finally, we analyze the notion of the ‘state-imposed’ value of carbon (also called shadow or reference value of carbon), which can be considered as one of the first step in formalizing the economic social value.JEL Codes: E6, O3, Q5