Fig. 6.

A generalized and simplified flowchart for deriving an overall composite index based on hierarchical aggregation. Of the references reviewed, 86% derived an overall composite index, and 58% of these used unequal weights in the aggregation of their dimensions (see Tables 3 and S2). The dotted line between the dimension boxes and the overall composite index box indicates that not all of the references reviewed derived an overall composite index. Here, dimensions also refer to domains, components or their equivalent. In some cases, sub-indicators, called variables in the figure, were also used (e.g., Royuela et al. 2003)