Urbanization deserves urgent attention from policy makers, academics, entrepreneurs, and social reformers of all stripes. Nothing else will create as many opportunities for social and economic progress. The urbanization project began roughly 1,000 years after the transition from the Pleistocene to the milder and more stable Holocene interglacial. In 2010, the urban population in developing countries stood at 2.5 billion. The developing world can accommodate the urban population growth and declining urban density in many ways.

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 environs affect identity and self-respect.

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.

Cities emerge from the spatial concentration of people and economic activities. But spatial concentration is not enough; the economic viability of cities depends on people, ideas, and goods to move rapidly across the urban area. This constant movement within dense cities creates wealth but also various degrees of unpleasantness and misery that economists call negative externalities, such as congestion, pollution, and environmental degradation.

Inexorable urbanization and formalization have been the expectations in development discourse. Indeed, measures of urbanization and formalization have been provided and used as indicators of development. But while urbanization has proceeded apace in developing countries, formalization has slowed significantly over the past quarter century. These disconnect raises questions for development analysis and development policy. Why did one expect urbanization and formalization to go together in the first place?

This report aims to extract lessons on slum upgrading and involuntary resettlement policies and practices learned from the process of addressing the Badia East case, which involved complex interactions between affected people, NGOs, the Bank and Lagos State Government.

Infrastructure can be an agent of change in addressing the most systemic development challenges of today s world from social stability to rapid urbanization, climate change adaptation and mitigation, natural disasters, and global issues such as food and energy security. Transformation through Infrastructure the updated World Bank Group Infrastructure Strategy FY12-15 - lays out the framework for transforming the Bank Group s engagement in infrastructure.

All countries have a formal economy and an informal economy. But, on average, in developing countries the relative size of the informal sector is considerably larger than in developed countries. This paper argues that this has important implications for housing policy in developing countries. That most poor households derive their income from informal employment effectively precludes income-contingent transfers as a method of redistribution.

This paper reviews the evidence about the effects of urbanization and cities on productivity and economic growth in developing countries using a consistent theoretical framework. Just like in developed economies, there is strong evidence that cities in developing countries bolster productive efficiency. Regarding whether cities promote self-sustained growth, the evidence is suggestive but ultimately inconclusive. These findings imply that the traditional agenda of aiming to raise within-city efficiency should be continued.

Man-made climate change is affecting water infrastructure in all regions of the world, affecting large numbers of people in their daily life and the development of their societies. As part of the World Bank Water Anchor's analytical and advisory work on water and climate change, consultants have investigated how private sector services to infrastructure may address the challenges related to climate change while, at the same time, improving development opportunities for people.

Local and Community Driven Development (LCDD) is an approach that gives control of development decisions and resources to community groups and representative local governments. Poor communities receive funds, decide on their use, plan and execute the chosen local projects, and monitor the provision of services that result from it. It improves not just incomes but people's empowerment and governance capacity, the lack of which is a form of poverty as well. LCDD operations have demonstrated effectiveness at delivering results and have received substantial support from the World Bank.