The Books Everyone Starts and No One Finishes, According to Amazon

Picking up a book is gratifying: look at me, not reading dumb listicles on the internet! Finishing a book, however, is a challenge. Which of this summer's top-selling books have the highest reader attrition? Dr. Jordan Ellenberg has a semi-scientific way to find out, using buyer-generated info from Amazon to identify this year's most unread book.

It's a charmingly simple (if not entirely rigorous) method: Dr. Ellenberg cruises the "Popular Highlights" listings for each title, which shows the five passages most frequently highlighted by Kindle readers. If most folks make it to the very last page, those passages should come from the front, the back, and everywhere in between. If everyone drops off in Chapter 3, the most popular passages will be focused in the first few pages.

Thus, if you average the page numbers of the top five highlights, and divide that number by the number of pages in the book, you get a percentage that (roughly) indicates the likelihood most readers finished the book. Dr. Ellenberg calls this the Hawking Index. It's a nod to Stephen Hawking's A Brief History of Time, a book everybody wants to have read but hardly anyone actually finished.

You should really check out Dr. Ellenberg's full list—there are some surprises! But here are the bottom four; the books that hardly anybody actually finished.

Lean In, by Sheryl Sandberg: Running at 12.3% on the Hawking Index, it seems most readers have delegated this task to an underling after just a few chapters.

Thinking, Fast and Slow, by Daniel Kahneman: At 6.8%, Prof. Kahneman's tour of the psychology of the human mind sounds a little dense for beach reading.

A Brief History of Time, by Stephen Hawking: Chalking up 6.6% on the index named for its author, this astrophysics tome is a little too much for most readers to bear. But it's no longer the number-one unread book, which, in some parallel universe out there, may just be the biggest achievement of all.

Capital in the Twenty-First Century, by Thomas Piketty: scoring a paltry 2.4%, even the title is making me doze.

Image: Shutterstock / R.Ashrafov