Why sickness and death rates do not move parallel to one another over time

Scholars sometimes claim that mortality and morbidity move parallel to one another over time. Using case studies from nineteenth-century England and W ales, this essay plots actual relationships in historical populations and e xplores why parallelism should not be expected. The implication of finding that mortality and morbidity chart independent courses is that they are eit her shaped by different factors or by the same factors operating in differe nt ways. Hence morbidity should not be expected to be controlled by policie s formulated to control mortality.