• What is population aging and how does it affect the age structure of a population? • What demographic processes produce population aging? • Summarized the evidence for population aging in the U. S.

1. Population aging is the process in which there is increase in the median age of the population. This might possible due to the the decrease in the fertility rate or younger children vulnerability. The disease or death rate is high among the elder population.

2. The population aging might occur due to the difference in the birth rate, death rate, immigration and emigration among the population.

3. The main reason for the population aging in the U.S. is due to the better medical facilities and  advancement in the health techniques. The increase in the old age people and due to the better employments.

transportation i would say maybe sorry it its not correct