Attributes of the models.

Grey shading indicates the variable changed in each group of models. See Section 3 for a discussion of the conceptual framework, which outlines the different parts that comprise the models. SI and WT in column 1 refer to the ‘Stochastic Instability’ and ‘Waiting Time’ models, respectively. Models 1–5 are in Appendix A. The distribution shapes each model can produce are described in sections where they are developed, and acceptable approximations to observations are log-normal, gamma or exponential above the mode.