The use of AI enables a new heuristic capacity for public authority budgets that we call precision. Indeed, AI technologies make it possible, on the basis of the application of intelligent algorithms and prediction techniques, to construct an economic planning that reduces the implementation deficit of the planning process, bringing forecast and actual result closer together. The increased speed and accuracy of the budgeting process (near-real-time construction, evaluation and reprogramming) is generated by the data-driven model that rewrites programming documents and enables precise, customised and adaptive public policies. AI technologies are not exempt from risks to democracy and the legal principles underpinning public action, but they can prove to be valuable allies of law if the new algorithmic public capacity is translated into a structured and transparent by design framework that guarantees algorithmic legality and aims to give effect to legislative and meta-legal clauses that have hitherto been difficult to translate economically and administratively. In the same way, AI technologies should not be limited to supporting the political decision-maker, but can enable the development of the level of accountability of public action that fosters a participatory process and a model of shared administration. This new perspective paves the way for an unprecedented modelling of economic planning and the entire administrative ecosystem. The paper explores the hypothesis of a precision economic planning based on the use of AI that favours the ex-ante understanding of the impacts of local authorities’ budgetary policies on the different generational cohorts. Precision accounting, an evolution of the traditional discipline, to which this work ideally tends, can offer a new administrative capacity at the service of programming that is not resolved in mere ideological choices or accounting labels but aims at an effectiveness of programmes and their impact, constructed data-driven and recalibrated in a continuous feedback. The objective is to change the government process through the support of data and artificial intelligence, democratising the budget and thus administrative action, making the decision-making process transparent and the administrative mandate assessable, thus consolidating the principle elaborated by the constitutional justice of the Budget Public Good, intended to synthesise, through a transparent allocation of resources, democratic choices.