Children's books are now significantly longer - thanks to JK Rowling and Harry Potter

American Library Association blog The Booklist Reader have looked at books aimed at children up to the age of 13 over the last forty years and recorded total page numbers, noticing an increase in length of 173%.

In 1976, the average children's book was 106 pages long, and that's increased to 290 in 2016 – most notably with a significant surge after the 1998 publication of JK Rowling's Harry Potter and the Philosopher's Stone, with book lengths jumping 152.88% between 1996 and 2016.

Children's author and Booklist Reader contributing editor Ilene Cooper and veteran librarian Carolyn Phelan looked at the data and "both offered the same two words: 'Harry Potter'."

Even Rowling's series itself follows the trend, notes Booklist, with her first novel clocking in at 320 pages and the final book in the series – Harry Potter and the Deathly Hallows – more than double that at 756 pages long.

It seems our appetite for Rowling's Wizarding World convinced writers and publishers that children would read – and indeed demolish – long works of fiction.

And the "Potter Effect" doesn't end there. The subsequent popularity of the fantasy genre has had an impact on the the average book length. "Fantasies tend to be really long,” Ilene explains. “Authors are building another world. Readers of fantasy want to get lost in those worlds.”