As the majority of ghostwriters sign nondisclosure agreements, it’s impossible to know exactly how many books are ghostwritten each year. The president of Arbor Books, which furnishes ghostwriters, told us, “From what I’ve seen, I’d imagine a billion dollar industry.” The president of a similar firm estimated that at least 25% of the New York Times nonfiction bestseller list is ghostwritten and that when a celebrity or politician is involved, “It’s nearly 100%.”

The Ghostwriting Business