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...

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...

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...

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...

The paper presents a major overhaul to the World Bank's past estimates of global poverty, incorporating new and better data. Extreme poverty-as judged by what "poverty" means in the world's poorest countries-is found to be more pervasive than we thought. Yet the data also provide robust evidence...

Knowledge about development effectiveness is constrained by two factors. First, the project staff in governments and international agencies who decide how much to invest in research on specific interventions are often not well informed about the returns to rigorous evaluation and (even when they...

While barriers to trade in most goods and some services including capital flows have been reduced considerably over the past two decades, many remain. Such policies harm most the economies imposing them, but the worst of the merchandise barriers (in agriculture and textiles) are particularly...

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 it...

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...

This paper first considers the impact on world food prices of the changes in restrictions on trade in staple foods during the 2008 world food price crisis. Those changes--reductions in import protection or increases in export restraints--were meant to partially insulate domestic markets from the...