We examine two sets of economies, (19th century U.S. states and 20th century less developed countries) where growth rates are positively correlated with initial levels of development to document how these dynamic increasing returns operate. We find that open economies do not display a positive...

Historically, urban growth required enough development to grow and transport significant agricultural surpluses or a government effective enough to build an empire. But there has been an explosion of poor mega-cities over the last thirty years. A simple urban model illustrates that in closed...

Africa is urbanizing rapidly, and this creates both opportunities and challenges. Labor productivity appears to be much higher in developing-world cities than in rural areas, and historically urbanization is strongly correlated with economic growth. Education seems to be a strong complement to...

Antipoverty policies assume that targeting poor households suffices in reaching poor individuals. We question this assumption. Our comprehensive assessment for sub-Saharan Africa reveals that undernourished women and children are spread widely across the household wealth and consumption...

New, “big” data sources allow measurement of city characteristics and outcome variables higher frequencies and finer geographic scales than ever before. However, big data will not solve large urban social science questions on its own. Big data has the most value for the study of cities when...

The fast and often chaotic urbanization of the developing world generates both economic opportunity and challenges, like contagious disease and congestion, because proximity increases both positive and negative externalities. In this paper, we review the expanding body of economic research on...

Standard measures of poverty may reveal nothing about whether the poorest of the poor are being lifted-up or left-behind, yet this is a widespread concern among policy makers and citizens. The paper assesses whether public spending on social protection benefits the poorest and hence lifts the...

While the 2008 financial crisis is global in nature, it is likely to have heterogeneous welfare impacts within the developing world, with some countries, and some people, more vulnerable than others. It also threatens to have lasting impacts for some of those affected, notably through the...