The Power of the President ... and the Thumb

How much does the President of the United States really matter? Stephen Dubner talks to former Defense Secretary Donald Rumsfeld, economists Austan Goolsbee and Justin Wolfers, and constitutional scholar Bernadette Meyler about how the President's actual influence can be measured; and Steve Levitt weighs in on how he thinks the President shapes the nation, and whether he'll be voting in the next election.

Also, hitchhiking has practically disappeared in America. But why? Was it really as dangerous as we believed? Even if so, what other factors were at play? Among our guests are data wizard Bill James, who says our risk aversion to hitchhiking makes it more dangerous, and transportation scholar Alan Pisarski, who looks at how hitchhiking can inform future transportation policy. Would our society be better off with more hitchhiking?

Learn more of listen again to this week's episode.