The President Is Missing is jointly ascribed to both the ex-president and the bestseller – but computer analysis suggests the prose was less than equally divided

As the world’s bestselling author, James Patterson has his name on a lot of covers. Usually, the font size his hallmark enjoys overshadows that of a lesser known collaborator. Contrary to the popular adage, you can tell a lot by a book’s cover. The message on Patterson’s covers is clear: he is the selling point. But this is not the case with Patterson’s most recent title, The President Is Missing, where the name of his co-author, Bill Clinton, shares equal prominence.

Reviewing the novel in the New Yorker, Anthony Lane remarks that “collaboration is a murky trade”. Perhaps so, but it can be made less murky by stylometric analysis, the purpose of which is to statistically cluster texts by style, based on authorial fingerprints. Simply put, stylometry uses computers to figure out who wrote a text. Last year, I co-authored a paper that used such techniques to determine how much Patterson actually contributes to writing his collaborative novels. The findings, published in Digital Humanities Quarterly 11.1, showed that Patterson’s less illustrious associates are the ones committing the vast majority of the prose to paper.

Our study raises considerable questions around authorship, and whether it is plot or language that makes a storyteller. It also explores the place of style in a literary marketplace where the novel is seen as the major commodity; the role of artistry is somewhat diminished when the aim is to sell an accessible and entertaining story. For “brand-managed” authors such as Patterson, writing is about the efficient production of leisure-time materials, a process to which eager junior colleagues can significantly contribute.

Lane was kind enough to draw from our study in his review, though our analysis, published before The President Is Missing had been announced, only left him with a natural sense of unsatisfied curiosity. “Who ghosted whom?” he asks. “Did Patterson supply the bones of the story, as is his wont, and Clinton tack on the flesh? Or did Patterson reverse his usual process, merely tinkering and smoothing after Clinton, musing on his years in office, had brought forth a plot – in essence, his reverie of responsible power?”

Thanks to methods developed by Maciej Eder, Lane’s questions can be answered. The findings are clear: Patterson’s is the dominant style throughout the novel – with the exception of the finale, where the signal shifts to Clinton. This is precisely what Lane concludes from his reading, describing the novel’s twilight as an exudence of the former president’s “politico-historical thoughts”.

Facebook Twitter Pinterest Stylometric analysis of The President Is Missing. Photograph: James O'Sullivan

This graph represents the novel on the x-axis, broken into segments: the thicker the bottom line, the more certain the decision made by the classifier, which can be intuitively interpreted as the proximity to the relevant author’s style. Considering Patterson’s fingerprint is represented by green, it is plain to see that, contrary to our previous study, this is a co-authored novel in which he was the scribe.

The authorial fingerprints are generated using a selection of Patterson solo-authored texts, alongside Clinton’s books My Life, Giving and Back to Work. Herein lies a slight limitation to this study: Clinton’s previous books are all non-fiction. While my experience is that authorial signals outweigh those produced by genre, the results would be more conclusive had Clinton previously tried his hand at fiction.

It is both troubling and fascinating to see literary capitalism reach this height. What better way to sell a book, than to have a mogul of commuter fiction combine with a former US president? When you have sold millions of books on the back of your brand, I suppose the only thing left to do is find an even more recognisable mark – at the very least, you find a name worthy of a similar font size.