The summer's least read book? Piketty's treatise on inequality

“Capital in the Twenty-First Century” by Thomas Piketty : 2.4%
Yes, it came out just three months ago. But the contest isn’t even close. Mr. Piketty’s book is almost 700 pages long, and the last of the top five popular highlights appears on page 26. Stephen Hawking is off the hook; from now on, this measure should be known as the Piketty Index.