Some observers have questioned the rationale for continued engagement by international development institutions in middle-income countries. But these countries face development challenges calling for continued partnership with the international development community. Moreover, partnership with...

When average incomes rise, the average incomes of the poorest fifth of society rise proportionately. This holds across regions, periods, income levels, and growth rates. But relatively little is known about the broad forces that account for the variations across countries and across time in the...