By Ken Olshanksy, CNN
Dr. Jim Yong Kim may have one of the best jobs in the world, but also the hardest.
As head of the World Bank, he has almost $60 billion to spend to fight poverty and boost the middle class. But poverty isn't giving up without a fight.
About 2.5 billion people live on less than $2 a day, a number that hasn't changed much in more than 30 years. And successful growth of the global middle class comes at a cost: A massive income disparity as the poorest are left behind.
Raising the standard of living across the world is crucial to keeping the world safe and secure. But Jim Yong Kim is not your typical banker. He is a doctor and anthropologist, with an extraordinary track record fighting disease in the poorest corners of the world.