“Just how similar passages showed up in two books is a tale of how the largely obscure $4 billion a year world of elementary and high school textbook publishing often works, for these passages were not written by the named authors but by one or more uncredited writers.” Using doubled passages on Homeland Security as a newspeg, the NYT delves into the somewhat sordid world of history textbook writing. Hmmm. From my experience, what the Times reports is true, but it’s not true of every book. I’ve done quite a bit of work revising supplementals for various history textbooks during my grad school tenure, and, at least for the ones I’ve worked on, the updates and revisions have come right from the top down, from the author or authors on the book’s cover.