He was chair of the Economics department at the University of Chicago and colleague to an impressive range of celebrated economists including friend Gary S. Becker.
As Palda wrote in 2013[1] In his 1974 and 1986 articles Sherwin Rosen asked what would happen if you were limited in how you could move about through characteristics space.
Rosen called such exchanges tied-sales.Rosen showed that tied sales could lead to the segregation of people by their types.
He argued that the worst effects of segregation could be palliated by a market that resolved supply and demand of complicated tied sales situations through a monetary payment he called an "equalizing difference".
In addition to implications for policy, Rosen's analysis of choice in characteristics space with tied sales specified the conditions under which the parameters of demand and supply function parameters for the underlying characteristics of goods could be deduced from so-called hedonic regressions.