When one sets out to interview the author of a 700-page book on economics (being published by a university press), it is generally smooth sailing. Publishers and writers crave the publicity; copies of the book are overnighted to the interviewer; emails from publicists asking “what else can I do for you?” begin to pile up.

In the case of Thomas Piketty, whose Capital in the Twenty-First Century is currently one of the best-selling books in the country, things are a little more difficult. Scheduling a mere phone conversation with Piketty seemed harder than setting up a meeting with the Pope. Piketty has been traveling from continent to continent promoting the book, and last week he needed a break from all the publicity before we could move forward with an interview. Meanwhile, the book is sold out, and so this interviewer was forced to read an e-version. (Harvard University Press is busy ensuring that more copies are printed.)

When I finally did reach Piketty at his office in Paris, we talked for nearly an hour. He spoke with a thick French accent, and was warm and engaging, even asking me questions about my opinion of his work. We discussed fellow economists who frustrate him, the best critiques of his book, and why he has no time for Karl Marx.

Isaac Chotiner: Why do you think your book has taken off?

Thomas Piketty: Some of the success of the book comes from the fact that there is concern with rising inequality.