Before joining the faculty at UCR in 1988, he taught at Princeton University, the University of Texas at San Antonio, and the Universidad Autonoma de Yucatan.
Patch is interested in the origins of revolution and underdevelopment in Latin America.
He specializes in the history of Indians during the period of colonialism, and the development of social, economic, and political structures. His research focuses on the history of Mexico and Central America. Patch is the author of several articles and a book, Maya and Spaniard in Yucatan . He has also been the recipient of a Doherty Fellowship, which led to lengthy residence in Mexico, and spent 1984-1986 in Spain as a Fulbright Fellow.