If most of the population are 'children' (people under 24) the economy will develop slowly. This is due to the fact that children have many needs. For example they need to go to school, they need healthcare, more food than adults, hobbies and more. If there aren't many adults to do these jobs (as most of the population is kids), most of these children will have limited access to these needs. Therefore, the development is slower since the children don't have these things. If this doesn't improve, when these children grow up and become adults, they won't be able to support their children in their needs as they won't be educated enough to do them. On the other hand, Bolivia's population is increasing by 1.6% each year and on average women have 2.6 children each.