\ Global Youth Development Index and Report 2016 2.6 Correlations 2.6.1  Youth bulge and youth development Results of the 2016 YDI show that youth development tends to be most sluggish in countries in which young people represent a large share of the population or are experiencing a ‘youth bulge’. Figure 2.22 suggests that YDI scores have an inverse relationship with the proportion of youth within the population. In countries with the most impressive levels of youth development, young people tend to be a relatively small part of the total population. However, this relationship is not entirely linear and there are significant exceptions to this pattern. There are many countries with a large youth population in the higher YDI categories. The horizontal spread in Figure 2.22 demonstrates that a youth bulge does not necessarily mean low levels of youth development in a country. Table 2.13 lists the ten countries with the largest proportion of young people as a share of the total population in 2015. There are at least four countries in the high YDI category where young people make up nearly one-third of the population. Additionally, there are at least eight countries in the high and very high YDI categories where youth constitute more than one-quarter of the population. These countries include Costa Rica, Malaysia, Brunei, Colombia, Bahrain and Jamaica. If the criteria of the relative size of the youth population is lowered to 20 per cent, there are many countries that have both large youth bulges and either high or very high levels of development. All these countries demonstrate that high levels of empowerment, achievement and social inclusion are possible for large populations of youth, and that the YDI can be a useful tool for guiding countries in this pursuit. While the negative correlation between youth bulge and levels of youth development does not prove any causality, it nonetheless demonstrates that countries with higher sizes of youth population are on average more likely to have lower levels of youth development. The implication for countries with a large youth population is that they have to put in more effort than others to achieve better youth development outcomes. Currently, there are at least 148 countries with a youth bulge, and nearly all Figure 2.22  The correlation between a country’s youth population and its 2016 YDI score 35% 30% Proprtion of youth 56 25% 20% 15% Youth bulge >20% 10% 0.3 0.4 0.5 0.6 0.7 0.8 Lower development 2016 YDI Source: Commonwealth Secretariat 0.9 High development Very high YDI Countries High YDI Countries Medium YDI Countries Low YDI Countries 1.0