In this section, we note a variety of problems with R 0 that are not covered in the previous sections. These include problems with the underlying structure of compartment models, the mismatch between an individual-based parameter and a population-level compartment model, and the failure of R 0 to accurately measure an outbreak of a new disease. Breban et al. [32] argued that in order to associate an R 0 to a model of ODEs, an individual-level model (ILM) which is compatible to the ODE model must be developed; only then can the R 0 of the ILM be unambiguously calculated. These ILMs are growing (not static) network models, with individuals added to a network of who infected whom based on global or local network rules. Then, R 0 is computed as the limit of the average number of outgoing links of individuals in a node that no longer accepts new links, as time goes to infinity. They showed that a broad range of R 0 values were compatible with a given ODE model.