William Labov is considered the founder of modern sociolinguistics. He preferred the label "language variation and change" to describe his work studying how language varies based on social factors. Labov was inspired to establish the theoretical relationship between language, individuals, and communities. He conducted seminal studies on Martha's Vineyard and in New York City that demonstrated sound changes correlate with social variables and can be observed through linguistic variation. Labov established foundational concepts for the field like the linguistic variable and the principle of accountability. His work paved the way for sociolinguistics to empirically study language in use and how it varies across social networks.