Joseph S. Sheehan was born in New York City on February 26, 1971, and attended Regis High School. He graduated from the University of Southern California in 1994 with a degree in journalism. Sheehan lives in the New York City area. He is one of the founders and was a co-editor of the first annual book of sabermetric baseball forecasts and analyses by Baseball Prospectus in 1996 as well as several later volumes. On October 10, 2007, Sheehan took on an additional role as Managing Editor of the newly founded Basketball Prospectus.