We start with a discussion about new indicators of wealth, and with an Action Research experiment. We analyze the forms of participatory expressions that are possible in different processes of quantification in relation to public action management. Instead of directly analyzing the uses of numbers in public action, we study the forms of participation that take place upstream and all along the process of construction of indicators, on which public action relies. We bring to light different conceptions of democracy underlying the process of production of numbers and we analyze the link between techniques of quantification and possible forms of “participation.”