190
13 Tolerance and Acceptability
Well-known examples of log-log straight thresholds are found in Christou et al.
(2006), NSW (2011), Hong Kong Government (1994), ANCOLD (2003) and Whitman (1984). They are depicted in Fig. 13.1.
By simply reasoning on the slope of the graphs of Fig. 13.1 one can immediately
see that:
• Whitman’s (1984) tolerance thresholds slopes depict a risk-prone society;
• Hong Kong (1994) curves are ISO-risk;
• NSW (2011) curves are risk-averse;
• EC (Christou et al. 2006) curves are strongly risk-averse,
• ANCOLD first depict an ISO-risk behaviour and then, from 100 casualties onward,
depict a risk-indifferent behaviour.
The Whitman tolerance is depicted in Fig. 13.2 together with data from accidents
of the times it was defined. In the graph in the original paper (Whitman 1984),
reproduced here as is, the “cost of a life” was equated to one million dollars with no
further emotion or discussion. That was considered just fine in those times. Today
we do not attribute a cost to human life, a notion often considered repugnant and
ethically unacceptable, but rather, we look at accepted capital expenditure in various
countries to save the life of a citizen potentially exposed to natural hazards to find a
“bounding value”. In other words, this book uses the mitigative investment a society
Fig. 13.2 Whitman tolerance data from accidents of those times. NB: “cost of casualty” assumed
to be 1 M USD
13 Tolerance and Acceptability
Well-known examples of log-log straight thresholds are found in Christou et al.
(2006), NSW (2011), Hong Kong Government (1994), ANCOLD (2003) and Whitman (1984). They are depicted in Fig. 13.1.
By simply reasoning on the slope of the graphs of Fig. 13.1 one can immediately
see that:
• Whitman’s (1984) tolerance thresholds slopes depict a risk-prone society;
• Hong Kong (1994) curves are ISO-risk;
• NSW (2011) curves are risk-averse;
• EC (Christou et al. 2006) curves are strongly risk-averse,
• ANCOLD first depict an ISO-risk behaviour and then, from 100 casualties onward,
depict a risk-indifferent behaviour.
The Whitman tolerance is depicted in Fig. 13.2 together with data from accidents
of the times it was defined. In the graph in the original paper (Whitman 1984),
reproduced here as is, the “cost of a life” was equated to one million dollars with no
further emotion or discussion. That was considered just fine in those times. Today
we do not attribute a cost to human life, a notion often considered repugnant and
ethically unacceptable, but rather, we look at accepted capital expenditure in various
countries to save the life of a citizen potentially exposed to natural hazards to find a
“bounding value”. In other words, this book uses the mitigative investment a society
Fig. 13.2 Whitman tolerance data from accidents of those times. NB: “cost of casualty” assumed
to be 1 M USD