When economists set out to measure economic growth and progress over time, one challenge is accounting for striking differences in the quality of goods. Computers, cell phones, and cars on the market today are not easily comparable to those available in 1990. But over the centuries, remarkably little has changed about the common construction nail. For that reason, today's guest explores American economic history through the story of nails. Studying nail production and costs over the past three centuries, Dan Sichel joins this episode of "Political Economy" to explain what we can learn from the humble nail.

Dan is a professor of economics at Wellesley College in Massachusetts and the author of "The Price of Nails since 1695: A Window into Economic Change."