The model recognizes the importance of the tie between prisoner population and prison growth but considers additional factors which mediate this relationship. Given increases in prisoner populations, the model posits that the extent of prison construction is determined by three broad classes of factors: accelerators, which increase the probability of construction, and buffers and inhibitors, which decrease the probability. First, the rudiments of the process model are sketched and the accelerator, buffer, and inhibitor variables are described. Next, the process model is developed more fully through an examination of prison expansion in ten example states. Finally, the implications of the model are explored. (Author abstract)