Figures 17 through 21 map the size of each age group as a proportion of a country’s total population against countries’ Index scores for the corresponding Age Group pillar. To provide visual orientation, each diagram has been divided into quadrants based on the world average proportion of each age group (y-axis) and the median Index score for the corresponding Age Group pillar (x-axis). In each diagram, if a country falls on the horizontal line, its proportional share of the age group concerned is close to the world average. If it falls above the horizontal line, the country’s demographic makeup exhibits a higher share of its population in the age group concerned than for the world average. If it falls below the horizontal line, the country’s demographic makeup exhibits a lower share of its population in the age group concerned than for the world average. The vertical line represents the median Index score for the corresponding Age Group pillar. If a country falls to the left of the vertical line, its “distance to the ideal state” on that pillar ranks in the lower half of countries. If a country falls to the right of the vertical line, its “distance to the ideal state” on that pillar ranks in the upper half of countries.

As indicated in Figure 17, there is wide variation in both the range of the Under 15 Age Group’s population share as well as in the human capital outcomes measured by the pillar scores. In the 15–24 and 55–64 age groups (Figures 18 and 20), the age group size has a lower variation globally, whereas the pillar scores still have a marked spread. The 25–54 age group (Figure 19) is generally the largest portion of the population for most countries. The 65 and over age group also exhibits a wide variation with regard to its total share in countries’ overall population makeup.

It may appear from a first glance—particularly at the Under 15 and 65 and Over Age Group pillar results—that the proportional share of the age group in a country correlates with its pillar score. However, on closer inspection, both the income and the regional affiliation of a country have a much stronger effect on the Human Capital Index performance of a country than the size of the age group. A deeper analysis of the results does not find any strong support for the notion that certain demographic structures, such as youth bulges or ageing populations, are inherently beneficial or detrimental to a country’s ability to develop or leverage its human capital potential. Accordingly, the population diagrams included in the Country Profiles in Part II of this Report aim to familiarize the reader and call visual attention to the importance for human capital development and planning of understanding and considering demographic structures and dynamics (such as child and old-age dependency ratios), without taking a prescriptive stance regarding what should be done about them. Human capital planning and investment choices have the biggest role to play in determining whether a country is able to harness the full human capital potential inherent in its unique demographic structure, income profile or geographic location.