Within representative democracies, participatory mechanisms have been progressively implemented, often based on a legal obligation to consult citizens on various subjects, such as public services, urban planning, the environment, etc. These mechanisms can include the selection of panels of people, by co-option or randomly, public meetings likely to interest a wider public, or the use of referendums or petitions. All over Europe, locally and nationally, these practices are becoming established in public spaces, in particular by mobilizing digital tools, and often go beyond the strict framework of legal obligations: for example, many municipalities have set up participatory budgeting systems to entrust citizens with deciding on the allocation of part of the municipal budget. It is no longer simply a matter of giving an opinion or organizing a debate among citizens that may precede a decision by elected officials, but rather of letting citizens decide on part of the allocation of collective budgets, even if the budgetary leeway often remains limited.