For the case of an exponentially growing epidemic, the estimates of the individual and household reproduction numbers, R and R * respectively, are shown in Figure 3 , along with the estimate of the number of people one person infects outside their household, R G . For R * , both the under-and over-estimating approximations are shown, along with estimates obtained from the simulated generation time distribution. As expected for this low-infectiousness scenario, the simulated values are closer to the overestimating approximation. The range between these approximations which bracket the true value is rather narrow, indicating that the method is predictive.