Hawking Index
The Hawking Index is a mock mathematical measure on how far people will, on average, read through a book before giving up. It was invented by American mathematician Jordan Ellenberg, who created it in a blog for The Wall Street Journal in 2014. The Index is named after English physicist Stephen Hawking, whose book A Brief History of Time is often dubbed, "the most unread book of all time".
Calculation
Ellenberg's non-scientific method of calculating the Index is to the "Popular highlights", the five most highlighted passages marked by Amazon Kindle readers of each title. A wide spread of highlights throughout the book mean that most readers will have read the entire book, scoring high on the Index. If the spread of highlights occurs only at the beginning of the book, then it means that fewer people will have read the book completely and will thus score low on the Index. When the Index was created, this information was easier to access as "Popular highlights" was available to everyone, but since then this information has only been made available to people who buy the books on Kindle.Hawking Index scores
When Ellenberg first used the Index, he used the following books as his examples.| Book title | Author | Hawking Index |
| Hard Choices | Hillary Clinton | 1.9% |
| Capital in the Twenty-First Century | Thomas Piketty | 2.4% |
| Infinite Jest | David Foster Wallace | 6.4% |
| A Brief History of Time | Stephen Hawking | 6.6% |
| Thinking, Fast and Slow | Daniel Kahneman | 6.8% |
| Lean In | Sheryl Sandberg | 12.3% |
| Flash Boys | Michael Lewis | 21.7% |
| Fifty Shades of Grey | E. L. James | 25.9% |
| The Great Gatsby | F. Scott Fitzgerald | 28.3% |
| Catching Fire | Suzanne Collins | 43.4% |
| The Goldfinch | Donna Tartt | 98.5% |