There are two reasons why we perform this sampling procedure rather than simply minimizing RMSE between predictions and observations. First, it reduces the impact of time steps in which there is notable model error on the resulting rate estimate, as many samples will not include these time steps. Second, the spread of the sample-specific rate estimates provides uncertainty quantification on the overall rate estimate. Specifically, we set the error bound on the overall rate estimate as the 5 th and 95 th percentiles of the sample-specific rate estimates. This approach does not impose any assumptions on the symmetry of the error bound.