Philadelphia English or Delaware Valley English is a variety or dialect of American English native to Philadelphia and extending throughout the city's metropolitan area, including southeastern Pennsylvania, South Jersey, and of northern Delaware, Apart from Philadelphia, the dialect is spoken in such cities as Camden, Wilmington, Reading, Vineland, and Atlantic City. Philadelphia English is one of the best-studied varieties of English, as Philadelphia's University of Pennsylvania was the home institution of pioneering sociolinguist William Labov. Philadelphia English shares certain features with New York City English and Midland American English. Philadelphia and Baltimore accents fall under what Labov described as a single Mid-Atlantic dialect, encompassing the middle of the Mid-Atlantic United States.