The proliferation of informal and illegal forms of access to urban land and housing has been one of the main consequences of the processes of social exclusion and spatial segregation that have characterized intensive urban growth in developing countries. Given the absence of adequate housing policies and the failure of the land market to offer sufficient, suitable and accessible housing options, millions of urban poor have to create their own shelter, either by invading private or public land or by buying land illegally and constructing their own housing. This phenomenon has attracted the attention of many researchers, policy makers and others worried about the grave socioeconomic, environmental and political implications for the urban poor and society at large. Peruvian economist Hernando de Soto is one of the most influential contemporary ideologues addressing this complex issue.