From these various statements may be extracted a set of aims which is capable of encompassing them all. Threading through them is a concern to improve urban productivity and to provide in human settlements better conditions within which to live, especially for those who are poor, and to do so in ways which are sustainable. This core set of objectives provides benchmarks against which may be assessed attempts to manage urban areas. While only one set of measures, it represents international aspirations to improve the conditions of a major portion of human existence. It describes conditions of social and economic development. As such, it is well placed to challenge other sets of objectives as being partial, less desirable or even trivial.