Effective poverty reduction policies need accurate measures of wellbeing. The introduction of Chile Solidario, a programme aimed at eradicating extreme and persistent poverty in Chile, provided an opportunity to re-assess the proxy tool used to identify poor households (CAS). There is a growing interest in moving towards more comprehensive measures of wellbeing than standard income or one-dimensional measures. Sen's capability approach provides a framework for developing such measures, which we extend to develop operational measures of objectively valued opportunity sets. The article argues that these provide a more effective informational base to evaluate wellbeing. It then applies these ideas to the CAS as the informational base of the newly created Chile Solidario. Les politiques de reduction effective de la pauvrete reclament des mesures precises du bien-etre. La mise en place du Chile Solidario, un programme qui vise l'eradication de la pauvrete extreme et persistante au Chili, a offert une opportuni...