Singapore has increasing greying population.
Japan is in worse situation. Japan's population is aging faster than that of any other country in the world.
Quote from Jeffrey Hays: "A declining birthrate and an older population means that as time goes on there will more retired people and relatively less working people, which means that working people are increasingly called upon to support the retirees with their labor. "
China got 2 demographic potential issues.
Increasing greying population.
Due to 1 child policy and Chinese preference for males to continue the family surname there is imbalance of too many males vs too few females.
Country with favourable situation:
Indonesia 60 percent of its 240 million populace under 30 years of age.