TCS Daily Editor Nick Schulz sits down with author Tim Harford to discuss his book "The Undercover Economist: Exposing Why the Rich Are Rich, the Poor Are Poor -- and Why You Can Never Buy a Decent Used Car!" Harford talks about organic food, trade and what advice he'd give Paul Wolfowitz. [MP3 format - 8 minutes, 21 seconds]

TCS Daily Editor Nick Schulz sits down with author Henry Petroski to discuss his book "Pushing the Limits: New Adventures in Engineering." Petroski weighs in on engineering in the age of terrorism; the fall of skyscrapers; and the endurance of the paper clip. [MP3 format - 6 minutes]