where δ is the discount rate, I is the identity matrix, and F and V are from the next-generation matrix decomposition. R d combines properties of both the basic reproductive number and the ultimate proliferation rate although it also inherits the nonuniqueness problems from the nextgeneration method. Nishiura [4] developed a likelihood-based method for estimating R 0 without assuming exponential growth of cases and offers a corrected value of the actual reproduction number. The author noted that R 0 is extremely sensitive to dispersal of the progression of a disease or variations in the underlying epidemiological assumptions.