Over more than four decades, Bangladesh’s Grameen Bank has disbursed some $37 billion in collateral-free loans to over 10 million of the world’s poorest people. But founder Muhammad Yunus still remembers the first $5 he ever lent. It was 1974 and Yunus had recently returned from a teaching position at Middle Tennessee State University to his native Bangladesh, which three years earlier had won independence from Pakistan in a blood-soaked civil war.