The great 21st-century migration into cities will present both a great challenge for humanity and a significant opportunity for global economic growth. This paper describes the diverse patterns that define this metropolitan migration. It then lays out a framework for understanding the costs and benefits of new arrivals through migration's externalities and the challenges and policy tradeoffs that confront city stakeholders.

Housing matters to the livability of cities and to the productivity of their economies. The failure of cities to accommodate the housing needs of growing urban populations can be seen in the proliferation of poorly serviced, high-density informal settlements. Such settlements are not new in the history of rapidly growing cities, their persistence results as much from policies as from economics and demographic transition. Slums have attracted most of the attention on urban housing in developing countries, and the Millennium Development Goals have given prominence to their reduction.

El asentamiento Arsenio Vásquez es fruto de una ocupación masiva de familias locales de la Federación Nacional Campesina y la regularización se dio a través de un acuerdo firmado entre la organización nacional y el Estado paraguayo en 2004. Se trata de una propiedad común donde las familias locales no tienen títulos individuales, pero sí documentos que respaldan la ocupación de sus fincas.

Housing matters to the livability of
cities and to the productivity of their economies. The
failure of cities to accommodate the housing needs of
growing urban populations can be seen in the proliferation
of poorly serviced, high-density informal settlements. Such
settlements are not new in the history of rapidly growing
cities, their persistence results as much from policies as
from economics and demographic transition. Slums have

The great 21st-century migration into
cities will present both a great challenge for humanity and
a significant opportunity for global economic growth. This
paper describes the diverse patterns that define this
metropolitan migration. It then lays out a framework for
understanding the costs and benefits of new arrivals through
migration's externalities and the challenges and policy
tradeoffs that confront city stakeholders. The paper

The accumulation of decent housing
matters both because of the difference it makes to living
standards and because of its centrality to economic
development. The consequences for living standards are
far-reaching. In addition to directly conferring utility,
decent housing improves health and enables children to do
homework. It frees up women's time and enables them to
participate in the labor market. More subtly, a home and its

Indonesia's Program Nasional
Pemberdayaan Masyarakat (PNPM) is the largest Community
Driven Development (CDD) program in the world covering all
urban wards (PNPM-Urban) and rural villages (PNPM-Rural) in
Indonesia. This policy note summarizes a comprehensive
process evaluation of the PNPM-Urban program which has been
carried by the Research and Development (RAND) corporation
in collaboration with survey meter, as well as a rapid

The present report was prepared on the
basis of the findings of an international workshop held from
September 12-14, 2005, in Salvador da Bahia, and was
attended by delegations of three to five practitioners from
12 cities in Latin America, Africa and Asia. It had two main
objectives: (a) to share experiences on innovative solutions
to provide electricity services in poor peri-urban and urban
areas; and (b) to develop a body of knowledge to be

Most of the world's population now
lives in urban areas, and in developing regions the
proportion living in cities and towns has risen from 35
percent in 1990 to 45 percent in 2010, from 1.4 billion to
2.5 billion people (Jacobsen et al. 2012). A 2008 World Bank
analysis estimated that a third of people living on less
than US$2 per day reside in urban areas, and United Nation
or UN-habitat estimates that just under 40 percent of urban

Across the developing world, public
goods exert significant impacts on the local rural economy
in general and agricultural productivity and welfare
outcomes in particular. Economic and social-cultural
heterogeneity have, however, long been documented as
detrimental to collective capacity to provide public goods.
In particular, women are often under-represented in local
leadership and decision-making processes, as are young

In 2006-07, the Water and Sanitation
Program (WSP) initiated research to identify barriers to
service delivery for the urban poor. The findings of the
research have been presented in the Guidance Notes on
Improving Water Supply and Sanitation Services to the Urban
Poor in India. The Urban Global Practice Team of WSP decided
to expand the ambit of this research to a global context as
the learnings were relevant to experiences across Africa,

Urbanization is the single most
important transformation that the African continent will
undergo this century. More than half of Africa's
population will live in its cities by 2040. In the face of
rapid urbanization, there is a narrow window of opportunity
to harness the potential of cities as engines of economic
growth, and use this as a powerful leverage to achieve
sustainable development and poverty reduction. Despite its