Indices of fragility

From 2021 see hereAnalytic and synthetic indicators of demographic, social and economic fragility in the different areas of the city, prepared by the Statistics Office of the Municipality of Bologna on an annual basis.The analysis is divided into three areas: demographic, social and economic; for each of them there is a synthetic indicator of potential fragility and a set of analytical indicators. Each of the three synthetic indicators is calculated from the analytical indicators of the respective scope, by means of a procedure that assigns them a score and subsequently performs aggregations. Since the analytical indicators have different units of measurement and non-homogeneous variability, it was decided to use the method of standardisation for the calculation of scores. Turning the basic data (analytical indicators) into scores (type z-score) ranging from about 70 to 130 and with an average of 100, it is easier to identify areas with a fragility level above average (indicator values greater than 100) and areas with a lower fragility level (indicator values below 100). To obtain the synthetic indicators of potential fragility, in each individual area, the scores were aggregated by operating a corrected arithmetic mean using a penalty coefficient that depends, for each area, on the variability of the individual scores relative to their average value. In addition to a more correct calculation procedure and a more intuitive interpretation of the indicator compared to the average value, this method makes it possible to compare over time the relative change with respect to the average of the statistical areas. Subsequently, from the three synthetic indicators of fragility, one for each area (demographic, social, economic), a synthetic “complex” indicator of fragility was calculated, as a weighted average of the three scope indicators. In addition to the fragility indicators of individual areas and the “complex” indicator, which allow a vertical reading of the territory, where it is possible to distinguish the most fragile and the least fragile areas, a “group analysis” was carried out; this methodology, through appropriate algorithms that combine all the variables, returns merges of statistical areas into similar groups for the characteristics considered. It offers a horizontal view of the territory, in which all the areas belonging to the same group are characterised by a series of common situations that determine the degree of fragility.