What major insights have emerged from development economics in the past decade, and how do they matter for the World Bank? This challenging question was recently posed by World Bank Group President David Malpass to the staff of the Development Research Group. This paper assembles a set of 13...

The basic economic model of labor supply has a very clear prediction of what should be expected when an adult receives an unexpected cash windfall: they should work less and earn less. This intuition underlies concerns that many types of cash transfers, ranging from government benefits to...