Paper mill challenges: past, present, and future.

Paper mills are fraudulent organizations that make money by writing fake manuscripts and offering authorship slots for sale to academic customers. Mill activity differs in scale to individual academic misconduct: many thousands of fake paper mill manuscripts have been successfully published in peer-reviewed journals. Despite this, paper mill activity is still relatively unrecognized outside the publishing industry. We discuss what is known about paper mill operations and how publishers, independent organizations, and individuals are working to prevent and detect mill activity. Research readers can also have a part to play in paper mill detection, and we provide detail on what to look out for.