That said, mass-market paperbacks have been on a precipitous decline lately, though TKAM’s success, particularly in the education market, makes it a notable exception. But many publishers are moving away from the format. Pressed for further comment, a HarperCollins spokesperson informed me that “Like many American classics, To Kill A Mockingbird’s primary paperback format will be the trade paperback edition.” That’s an important distinction: The general trend in publishing has been against the mass-market and toward more expensive (and durable) editions—many American classics, including The Great Gatsby and The Grapes of Wrath no longer have mass-market editions.

Of course, the book will still be available in any public library in the country, and used copies are available on Amazon for prices as low as 40 cents (plus shipping and handling). But the disappearance of the mass-market edition could have a significant impact on schools. The fact that To Kill a Mockingbird is both so accessible to young readers and so widely taught in America is crucial to its cultural importance. In 1988, the National Council of Teachers of English reported that To Kill a Mockingbird was taught in a whopping 74 percent of schools and that “Only Romeo and Juliet, Macbeth, and Huckleberry Finn were assigned more often.” Today, To Kill a Mockingbird has almost certainly surpassed the controversial Finn as the most assigned novel in America’s middle- and high schools, and those often cash-strapped schools are far more likely to buy the cheaper mass-market edition than the more expensive trade paperback. According to the email sent by Hachette to booksellers, “more than two-thirds of the 30 million copies sold worldwide since publication have been Hachette’s low-priced edition.”

Without a mass-market option, schools will likely be forced to pay higher prices for bulk orders of the trade paperback edition—and given the perilous state of many school budgets, that could very easily lead to it being assigned in fewer schools. (Schools typically receive a bulk sale rate that gives them more than 50 percent off of the list price of a book—they most likely pay less than $4.50 per copy of the mass-market paperback of TKAM, whereas a copy of the trade paperback would cost no more than $7.50.) Hachette is upfront about this possibility: a bullet point in the email reads, “The disappearance of the iconic mass-market edition is very disappointing to us, especially as we understand this could force a difficult situation for schools and teachers with tight budgets who cannot afford the larger, higher priced paperback edition that will remain in the market.”

Without a mass-market option, schools will likely be forced to pay higher prices for bulk orders of the trade paperback edition.

Although we can’t make any claims with certainty without exact royalty information, traditional publishing economics suggest that Lee’s estate will now receive more money per copy of To Kill a Mockingbird sold under the new arrangement. Mass-market paperbacks typically receive higher royalty rates than trade paperbacks, but often generate lower per sale royalties. As of 2013, standard royalty rates were 7.5 percent on trade paperbacks and 8–10 percent on mass-market books, though Lee’s terms are almost certainly more beneficial than industry averages, given her profile and the consistent level of sales To Kill a Mockingbird generates. In any case, even with a slight-to-moderate decline in sales, the Lee estate stands to make more money in royalties, now that the trade paperback, and not the mass-market edition, will be the cheapest, and therefore best-selling, edition. HarperCollins did not respond when asked for comment on this specific issue.