Common-pool resources are of fundamental importance in biology and the social sciences. The use of a shared limited resource is an exemplar of a situation in which individuals can behave cooperatively, through modest consumption, or selfishly, through excessive consumption (Hardin 1968, 1998; Berkes et al. 1989; Ostrom et al. 1999; Ostrom 1999; Frank 1989; Foster 2004). The essential paradox co...