How perspective-based aggregation undermines the Pareto principle

The Pareto principle is a normative principle about preferences that advocates concordance with unanimous preference. However, people have perspectives not just preferences. Evaluating preferences requires that we understand the reasons that people have for them and the overall perspectives from which they arise. Philippe Mongin has argued that the Pareto principle loses its normative force when different people hold their preferences for different reasons so that we must take reasons into account. This article advocates that we take people’s broader perspectives into account. I argue that when people form their preferences by aggregating a collection of criteria, then taking these criteria directly into account and considering the broader perspectives and principles held by people will naturally lead to violations of the Pareto principle.