No, it’s supposed to be annual spend. However it’s worth noting that this is a simplified model which assumes a particular relationship between annual spend and historical spend (namely it assumes that spending has grown and will grow on an exponential).
R(0) should be total historical spend right? Rather than annual spend?
No, it’s supposed to be annual spend. However it’s worth noting that this is a simplified model which assumes a particular relationship between annual spend and historical spend (namely it assumes that spending has grown and will grow on an exponential).