A population pyramid is a tool used to simplify population data about a region or city to analyze the age and gender of any population. Using these visualizations, we are able to predict future population growth or reduction as well as observe current population trends. What follows are analyses of population trends occurring in three major Californian cities.
Bakersfield, CA | The population pyramid of Bakersfield, CA increases substantially in width at younger ages. Specifically, the pre-reproductive age group is much larger than the reproductive age group which is larger that the post-reproductive age group. This indicates that the population is increasing and will continue to increase indefinitely, because as each generation grows old enough to reproduce, there |
will be a greater number of people having children and therefore more children. This cycle will continue as long as the total birth rate exceeds the replacement birth rate that is just over 2.0.
Redding, CA | Redding's population pyramid displays a much more stable population than Bakersfield's. The overall trend is an equal population among age groups, which translates to an unchanging population. There are a couple of bulges at around the 50-60 year old age group and 20-30 year old age group, however these bulges act only to make the overall age distribution not quite normal; t,hey should not cause |
an overall decreasing or increasing trend in the population, as the bulges appear about equal in size. The bulges could be caused by the baby boomer population in America that then had children at approximately replacement birth rate. As long as the birth rate remains at replacement levels, bulges will continue to appear about every 30 years, but population will stay relatively constant.
Irvine, CA | The population pyramid of Irvine shows an overall negative population trend. The younger age groups, particularity pre-reproductive ages, have a much smaller population than older age groups. This results in a constantly decreasing population, as when the younger age groups begin having children there will be less reproductive couples and therefore less children. |
This decline in both young people and overall population was caused by a total fertility rate that was less than the replacement fertility rate, which in turn was possibly caused by more professionally focused or business oriented people that do not value children as a life priority.