The study , " Boys Will Be Boys : Gender , Overconfidence and Common Stock Investment , " was published in 2001 by Brad M. Barber , a finance professor at the University of California , Davis , and Terrance Odean , now a professor of banking and finance at the Haas School of Business at the University of California , Berkeley ( faculty.haas.berkeley.edu / odean / papers / gender / gender.html ) .