In 2014, the policy of promoting Local Agenda 21 programs in France came under heavy criticism, mainly because of the lack of evaluation, especially in quantitative terms. The Cour des Comptes (French Court of Auditors) pointed out in Report (Référé) no. 70375 of July 9, 2014 : “[…] the frequent absence of outcome indicators and the total absence of any ex ante or ex post financial evaluation of their effects”. To address the lack of evaluation, this paper aims to provide an estimate of the impact on per capita income of the adoption of the Local Agenda 21 programs in French municipalities. The estimation is preceded by a reflection on the difficulty of evaluating sustainable development initiatives.En 2014, la politique de promotion des Ag...