Investigating Cancer Inequalities in Urbanizing Texas with Plausible Reasoning

This article contributes to geographical methodology by presenting an epistemology of plausible reasoning (PR) as a complement to realist and reflexive frameworks for science. I introduce PR's theory of evidence, after Harold Jeffreys and George Pólya, and then extrapolate principles for nonexperimental study designs. This article leverages these principles to structure an investigation into the causes of a racial disparity in the colorectal cancer (CRC) burden in the Houston and Dallas-Fort Worth metropolitan areas. Centered on a series of empirical questions pertaining to racial ghettoization, contemporary urbanization, and cancer inequalities, the study uncovers important geographic and social changes in the CRC burden in the study areas between 1999 and 2019. These include the emergence of a substantial class-related inequality in CRC incidence, the rise of aggregate racial disparities in CRC incidence outside of historically ghettoized areas, and an overall intensification of spatial CRC inequality. Drawing on fundamental cause theory and critical urban studies, I propose that these changes are a product of the uneven spread of new preventive technologies (screening colonoscopy) amid extensive and polarizing urbanization processes that are reshaping these regions. The study highlights the value of incorporating concern for dynamic macrostructures and political economy into analyses of spatial health data, and illustrates how PR can contribute to such work.