4.1. CALCULATION OF OVERALL VULNERABILITY
Although maps of individual component scores can be useful, it is easiest to assess
overall social vulnerability throughout a region if the multidimensional components can be combined into a single measure (Clark et al. 1998). In the present case, the
simplest way to combine component scores into a single measure would be to
average the three component scores for each block group (Figure 8). However,
averaging component scores poses two significant problems. The first problem is
the construction of a weighted average. Simple averages can be used if all components
contribute equally to vulnerability, but if a researcher decides that certain
components contribute more to overall social vulnerability, he or she must make subjective decisions to create a weighting scheme. The second problem with using
averages is that they may obscure high scores on one component when averaged
with low scores on the other components. However, extreme values on even one
component may indicate areas particularly in need of attention.