Peter Blau

Peter Michael Blau (February 7, 1918 – March 12, 2002) was an American sociologist and theorist. Born in Vienna, Austria, he immigrated to the United States in 1939. He received his PhD at Columbia University in 1952, and was an instructor at Wayne State University in Detroit, Michigan from 1949–1951, before moving on to teach at the University of Chicago from 1953 to 1970. In 1970 he returned to Columbia University, where he continued to teach until 1988. From 1988 to 2000 he taught as an emeritus professor at University of North Carolina, Chapel Hill in the same department as his wife, Judith Blau.

His sociological specialty was in organizational and social structures, in particular bureaucracy. He produced theories relating to many aspects of social phenomena, including upward mobility, occupational opportunity, and heterogeneity. He also produced theories on how population structures can influence human behavior.

One of Blau's most important contributions to social theory is his work regarding exchange theory, which explains how small-scale social exchange directly relates to social structures at a societal level.