Principles of Linguistic Change, 3 Volume Set

William Labov is Professor of Linguistics and Director of the Linguistics Laboratory, University of Pennsylvania. His major studies include The Social Stratification of English in New York City (1966), Sociolinguistic Patterns (1972), Language in the Inner City (1972), Principles of Linguistic Change: Internal Factors (Wiley-Blackwell, 1994), Principles of Linguistic Change, Volume II: Social Factors (Wiley-Blackwell, 2001), and Principles of Linguistic Change, Volume III: Cognitive and Cultural Factors (Wiley-Blackwell, 2010). With S. Ash and C. Boberg, he published the Atlas of North American English in 2006.