This review essay provides an overview of Sen's revised edition of Collective Choice and Social Welfare (2017), and examines the relevance of its arguments in the context of Peru. It focuses on three main points: a social choice approach for addressing global problems; an expanded informational basis for making judgments; and a public reasoning view of collective decision-making. It critically analyses the human and social development strategy followed by the Peruvian government in recent years, and in particular the capacity of public reasoning to reflect and sustain the priorities of the poorest and marginalized in the public policy agenda.