Professor Oliver Williamson was awarded the 2009 Nobel prize in economics, along with Professor Elinor Ostrom, for his analysis of economics governance and of the boundaries of the firm. He was a member of the Penn Economics faculty from 1965-1983 (Associate Professor from 1965-58, Professor from 1968-83, and Charles and William L. Day Professor of economics and social science from 1977-1983). Much of the research for which he was awarded the Nobel prize was carried out during his time at Penn.
For further information see The Sveriges Riksbank Prize in Economic Sciences in Memory of Alfred Nobel 2009.