Books are much more affordable and accessible today than they were in the past, thanks to innovations in printing and digital technology. This article explores how Gutenberg’s printing press and Project Gutenberg’s eBooks have dramatically reduced the cost and increased the availability of books over time.

Gutenberg innovated the printing press around 1440. At that time, the average book cost around 135 days of labor, ranging from 15 days for a short book to 256 days for a major work. If each day contains eight hours of work, the average book will cost 1,080 hours. Today, blue-collar hourly compensation rate in the U.S. (wages and benefits) is around $32.54. Holding everything else constant, if there had been no book innovation since 1439, the money price of a typical book would be $35,143 today.

On July 4, 1971, Michael S. Hart created one of the first eBooks when he typed the Declaration of Independence on his computer and distributed the file to all his friends. He went on to found Project Gutenberg to encourage the creation and free distribution of eBooks. In the last 50 years, with the help of thousands of volunteers, the project has created a 67,000-volume library of books in over 60 languages and dialects.

If it weren’t for Gutenberg and his press and Hart and his computer, it would cost $2,354,594,400 to have such a 67,000-volume library. Yet that library is almost free today. As the Nobel Prize-winning economist Paul Romer would say, knowledge has increasing returns. Knowledge tends to make it easier to create and discover new knowledge. Knowledge can and sometimes does “go exponential.”

In 2022 we can all enjoy reading a great book for free and use our extra 1,080 hours to create some other valuable new knowledge to share with the rest of the world.