Final answer:
Well-off countries experience lower birth rates and an increased elderly population due to factors like education for women, better nutrition, and good sanitation, which contribute to a demographic shift towards smaller families and longer lifespans.
Step-by-step explanation:
In economically well-off countries, several factors contribute to the decline in birth rate and an increase in the population over 75 years old. Among these, female access to educational resources is crucial. When women are educated, they tend to have fewer children and do so later in life. This aligns with the demographic shift observed in developed countries, where economic conditions promote smaller families and investment in fewer children. In turn, these children receive better care and go on to live longer, healthier lives.
Nutrition also plays a significant role as better nutrition leads to improved health outcomes, contributing to longer lifespans. Good sanitation and personal hygiene further decrease the spread of diseases and enhance longevity. Together, these improved living conditions increase life expectancy and reduce the need to have more children, as survival into old age becomes more certain.
On the other hand, factors like inadequate healthcare during pregnancy, a high incidence of infectious disease, and widespread emigration would not contribute to a decline in birth rates and an increase in the elderly population in a high-income country. These factors are more commonly associated with low-income countries and can act to increase birth rates while reducing the aging population due to increased mortality.