intermediate categories. For example, the environment can be broadly divided into
“impact of emissions on the environment” and “consumption of environmental
resources,” the economy as “economic efficiency” and “equity in economic distribution,” and society as “social amenities” and “social safety.” Each indicator is
shown as a category below these. Indicators with an asterisk (*) are limiting
indicators, and the rest are maximization indicators. Table 9.2 presents a list showing
the thresholds for the respective indicator units, data sources, and limiting indicators
for the thresholds.
9.6 Sustainability Assessment of Megacities
This chapter presents the results of applying the City Sustainability Index prototype
to megacities. The term “megacity” refers to a city with an urban population of at
least 10 million people, but the actual urban area of a megacity is not clearly defined
beforehand. In this chapter, 18 megacities elicited from population data were
established as subjects of assessment (Table 9.3).
While it is possible to make comparisons between pairs of cities (one pair at a
time), regarding individual maximization indicators, individual comparisons of the
18 megacities here would only cause information overload. Therefore, the concentration of information to some extent was necessary. With this objective in mind, we
undertook standardization of maximization indicators after relativizing the 18 megacities using a z-value where the worst city was assigned a ranking of 0 and the best
city 100. The method of relativization and standardization we employed was the
same as the method for producing composite indicators consisting of plural individual indicators (OECD 2008). However, for the limiting indicators, we did not
undertake this type of concentration based on relativization and standardization at
all, and attention here must be paid to the fact that sustainability is judged on an
individual basis against the threshold, which is the absolute standard.
Figure 9.2 shows assessment results of the sustainability of the 18 megacities.
The line graph descending to the right shows the total of the standardized numerical
values of the maximization indicators with equal weights, in other words, the total
economic and social benefits. These numerical values do not have any units and
there is no significance in the absolute scale of the numerical values because they are
measured by the positions in the range of 18 megacities. Therefore, scale markings
on the vertical axis have been omitted. The megacities are arranged in order of size of
the total maximization indicator value. The bar graphs on the vertical axis show the
results of determination as to whether conditions for sustainability are being met for
the five types of limiting indicators. Shaded sections of a limiting indicator indicate
that that limiting indicator is not sustainable.
A look at the assessment results (Fig. 9.2) shows that there are five megacities that
fulfill limiting conditions for all five limiting indicators, and they are located in
developing countries. Therefore, the low level of economic development in those
cities may be a facilitating factor in meeting the environmental limitations. Next, a
174
K. Mori
“impact of emissions on the environment” and “consumption of environmental
resources,” the economy as “economic efficiency” and “equity in economic distribution,” and society as “social amenities” and “social safety.” Each indicator is
shown as a category below these. Indicators with an asterisk (*) are limiting
indicators, and the rest are maximization indicators. Table 9.2 presents a list showing
the thresholds for the respective indicator units, data sources, and limiting indicators
for the thresholds.
9.6 Sustainability Assessment of Megacities
This chapter presents the results of applying the City Sustainability Index prototype
to megacities. The term “megacity” refers to a city with an urban population of at
least 10 million people, but the actual urban area of a megacity is not clearly defined
beforehand. In this chapter, 18 megacities elicited from population data were
established as subjects of assessment (Table 9.3).
While it is possible to make comparisons between pairs of cities (one pair at a
time), regarding individual maximization indicators, individual comparisons of the
18 megacities here would only cause information overload. Therefore, the concentration of information to some extent was necessary. With this objective in mind, we
undertook standardization of maximization indicators after relativizing the 18 megacities using a z-value where the worst city was assigned a ranking of 0 and the best
city 100. The method of relativization and standardization we employed was the
same as the method for producing composite indicators consisting of plural individual indicators (OECD 2008). However, for the limiting indicators, we did not
undertake this type of concentration based on relativization and standardization at
all, and attention here must be paid to the fact that sustainability is judged on an
individual basis against the threshold, which is the absolute standard.
Figure 9.2 shows assessment results of the sustainability of the 18 megacities.
The line graph descending to the right shows the total of the standardized numerical
values of the maximization indicators with equal weights, in other words, the total
economic and social benefits. These numerical values do not have any units and
there is no significance in the absolute scale of the numerical values because they are
measured by the positions in the range of 18 megacities. Therefore, scale markings
on the vertical axis have been omitted. The megacities are arranged in order of size of
the total maximization indicator value. The bar graphs on the vertical axis show the
results of determination as to whether conditions for sustainability are being met for
the five types of limiting indicators. Shaded sections of a limiting indicator indicate
that that limiting indicator is not sustainable.
A look at the assessment results (Fig. 9.2) shows that there are five megacities that
fulfill limiting conditions for all five limiting indicators, and they are located in
developing countries. Therefore, the low level of economic development in those
cities may be a facilitating factor in meeting the environmental limitations. Next, a
174
K. Mori