Middle income countries (MICs) are facing rapidly evolving development challenges as their economist mature and integrate into the global economy. As a group, the 86 MICs account for about one -- fifth of world output, and their per capita income has grown by almost 4 percent annually since 1995. Yet there are still home to one -- third of the world's poorest citizens, living on less than 2 per day. The World Bank has provided US163 billion in loans to these countries since 1995 and it allocates about half of its administrative budget to working with them. Today, as a group these countries h