An estimated one-third of all urban residents live in informal settlements or slums—the vast majority in developing countries. Conditions in such areas vary widely from dismal, temporary shelter in squatter settlements to relatively well-constructed, informal housing that may persist for decades.
Common characteristics include uncertain tenure status, poor basic services such as water and sanitation, low-grade construction and overcrowded living conditions. Apart from physical deprivation, slum dwellers also often face more subtle disadvantages such as poor labor market integration and the social stigma attached to an inferior residential location. With continuing rapid growth of urban areas, improving the life of slum dwellers is a high priority for national and city governments and the international community.
Research conducted in recent years has focused on evaluating the value of public services, how service delivery can be improved, and how they can be better financed. Much of this work relied on detailed household surveys in four cities in India.