Economics Textbook Replaces Tiger Woods With Tom Brady

March 22, 2011 — -- Tiger Woods may have been so busy promoting new video game, Tiger Woods PGA Tour 12, that he missed the big news in economics.

A new version of a widely-used economics textbook, "Principles of Economics," no longer uses Tiger Woods as an example to explain economic theory.

Previous editions of the textbook used an example entitled, "Should Tiger Woods Mow His Own Lawn?" The sixth edition of the book replaced the previous example with one featuring quarterback Tom Brady, as first reported by the Harvard Crimson.

The book's author, Harvard economist Greg Mankiw, explained the decision to ABC News.

"From my perspective, this was a relatively small change," wrote Greg Mankiw in an email to ABC News.

"Why did I make it? I wanted students to focus on the economics of comparative advantage—the main point of this section of the book. I was afraid that keeping Tiger Woods in the hypothetical example would have raised thoughts of an altogether different set of issues."

Prior to the textbook using Tiger Woods, Mankiw said the book featured Michael Jordan, before the famous basketball player retired. Mankiw listed a number of other changes in the textbook in his blog.

Mankiw told the Harvard Crimson that he and his editor chose New England Patriots quarterback Tom Brady because he was another celebrity athlete.

Woods is currently competing in the PGA Tour's Arnold Palmer Invitational in Florida, which ends on Sunday.

He has struggled since his return to golf after a messy divorce. In 2010 Woods failed to finish in the top three in any of the 12 tournaments he entered. So far this year in three events, he's also missed the top spots. This has dropped his ranking from No. 1 in the world to No. 100 after holding first place from 2007-2009.