William Julius Wilson (born December 20, 1935) is an American sociologist. He is a professor at Harvard University and author of works on urban sociology, race and class issues. Laureate of the National Medal of Science, he served as the 80th President of the American Sociological Association, was a member of numerous national boards and commissions. He identified the importance of neighborhood effects and demonstrated how limited employment opportunities and weakened institutional resources exacerbated poverty within American inner-city neighborhoods.