The marginality concept calls for the integration of poverty concepts with those of social exclusion, geography, and ecology. The difficulties in reaching people at the margins of systems are explained by a set of distances, (i.e., physical distances such as being located in remote or harsh environments), social distances (being excluded, discriminated against, or not having rights or access to services or opportunities), but may also be related to technological and institutional infrastructure deficiencies. A review of policies intended to reduce marginality suggests that none of the marginality determinants need to be accepted as long term. Coherent policies and actions, however, need to match the systemic causality of marginality in order to be effective.