Chambers put these empirical findings on a conceptual level and argued that vulnerability has an external and internal side: People are exposed to specific natural and social risk. At the same time people possess different capacities to deal with their exposure by means of various strategies of action (Chambers 1989). This argument was again refined by Blaikie, Cannon, Davis and Wisner, who went on to develop the Pressure and Release Model (PAR) (see below).