Final answer:
An imbalanced initial age structure results in demographic issues with different challenges faced by developed and undeveloped countries. While developed countries often have an older demographic, undeveloped countries tend to have a larger young population due to higher birth rates and lower life expectancy.
Step-by-step explanation:
Imbalanced initial age structure leads to population growth that is not uniform and can result in demographic challenges. A skewed age structure can stem from various factors that influence birth rates, survival, and life expectancy. For instance, developed countries with slow population growth often have an age structure that includes fewer young and reproductive-aged individuals and a higher proportion of older individuals. In contrast, economically undeveloped countries show greater proportions of children and fewer elderly people, primarily due to higher birth rates and lower life expectancy associated with less optimal living conditions.
Therefore, age structure is closely related to the level of economic development in a region. As the age structure changes, nations must adapt to shifts in demand for various social services and must account for the economic impact of a larger or smaller workforce. It reflects the demographic transition associated with shifts in a population's age distribution as countries move from high birth and death rates to low birth and death rates through stages of economic development.