Morrow is currently working on a book that explores the origins of Modern City Planning as a response to difference (social, economic, ethnic, etc) in the industrial city titled Dirt, Disease and the Devil: the Origins of Modern Urban Planning in Toronto the Good. This work uses evidence in Toronto at the turn of the twentieth century to illustrate how various 'deviant' behavior (as defined by the state and civil society at the time) invoked responses that he argues laid the foundations for comprehensive city planning and the tools of its invention (zoning, public housing, the neighborhoods unit, etc).
His PhD research takes off from here, by exploring responses to difference after the Second World War. He is examining how the private sector responded to difference -- specifically, the privatization of urban space, including the emergence of private government (neighborhoods associations, condominiums, gated communities, etc) and its effects on the social and physical form of cities. Los Angeles is the locus of this inquiry.