Before revision:  We analyse the Diamond model, the Supply Chain modeland the Noria model, which are particularcases of the Jungle model as well.We show the Diamond model experiences a quasi phase transition for a not unreasonable set of empirical parameters .
After revision:  We analyse the Diamond model, another instance of the Jungle model, experiences the so called quasi phase transitions; in particular, both the U.S. subprime and the European sovereign crises are shown to be potential examples of quasi phase transitions. We argue the three known sources of default clustering (contagion, macroeconomic risk factors and frailty) can be understood under the unifying framework of contagion .