This isn't exactly about the romance genre, I don't think, but since IASPR's remit is about popular romance more widely I thought some people might be interested in Robin Virginia Smiles's dissertation on "Romance, Race and Resistance in Best-Selling African American Narrative."
The abstract is available here
but I'll give an excerpt from it:
This dissertation critically examines popular romantic fiction by African American writers and argues for its inclusion in the canons and curricula of African American literary studies. While novels that privilege themes of love and romance and that appeal primarily to a mass-market audience have tended to be cast as antithetical to matters of racial uplift and social protest, my work reverses this bias, establishing such texts as central to these concerns. [...] I identify the "racial project" undertaken in the popular romantic fiction of three best-selling African American writers in the latter-half of the twentieth century-- Frank Yerby, Toni Morrison, and Terry McMillan.
Proquest gives the following identifying details for the dissertation: Smiles, Robin Virginia, Ph.D., University of Maryland, College Park, 2009, 189 pages; AAT 3359426