It’s the banking tool that got millions of people around the world to stop wasting money on the lottery. So why won't state and federal officials in the U.S. give it a chance?

The U.S. president is often called the "leader of free world." But if you ask an economist or a Constitutional scholar how much the occupant of the Oval Office matters, they won't say much. We look at what the data have to say about measuring leadership, and its impact on the economy and the country.