Meanwhile many poor countries are remarkably young. The population of the world’s least-developed countries is projected to double in a few decades. While there are potential benefits to having a youthful and active population, there will be too many young people to employ in certain countries, likely increasing poverty rates. Evidence indicates that very young populations both harm democracy and heighten the risk of conflict.

Migration from poor countries to rich countries can help mitigate the approaching demographic crises by balancing dependency ratios, or the proportion of workers to the elderly and children, of individual countries. Subtracting unemployed youth from poor countries can reduce their problems, while adding young workers to aging countries can improve the capacity of governments to confront their challenges.