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Marin County is as "old" as Italy if not Japan

Based on my earlier research at Generating a Marin County population projection, I knew that Marin County was "old" in terms of demographics. This is because, since 2000, Marin County's population has grown much slower than either California or the US (left-hand graph below). Its population growth is better aligned with Italy (right-hand graph below).


Additionally, Marin County's life expectancy is way longer than the US. It is even longer than the one for Italy or Japan. See more on the subject here Is Marin County a Blue Zone?


Slow population growth combined with long life expectancy makes for old-looking age pyramid graphs.

Marin's age pyramid is way older than California's or the US

You can see that on the pyramid graphs below. Marin's pyramid already looked like an inverted urn by 2000 and even more so by 2021, indicating more older individuals and fewer younger ones. By comparison, both California and the US have maintained a relatively resilient proportion of youngsters.


The main takeaways from the pyramid graphs above include:

Marin's age pyramid structure is very similar to Italy and Japan

You can observe that by looking at the age pyramid graphs below.


When focusing on the most current data (2021), you see that Marin County is way older than either California or the US.


And, Marin County is similar to Italy and Japan.


Marin's wave graph is way older than California's or the US

A wave graph is informative as it is the equivalent of consecutively aggregating yearly pyramid graphs from 1970 to 2021 or 51 pyramid graphs! And, the wave graph gives you information on the yearly population change of each age tranche over time.

The wave graphs below confirm that Marin is way older than California or the US.


Main takeaways from the above wave graphs:

Marin's wave graph is very similar to Italy and Japan


Main takeaways from the above graph:

Long-term population prospect

These three regions with such rapidly aging pyramids and wave graphs are positioned to potentially experience a dramatic decline in population over the next two or three centuries. This is a prospect I modeled recently, including projecting Marin County's population and benchmarking it with a similar projection for Italy.

Projecting Marin County population out to 2300


A prospective long-term precipitous decline in population is not limited to Marin County and Italy, it is a common possibility throughout much of the developed World. For more on the subject:

Will China, Japan, and other countries make it to 2300?

NYT article on the prospective decline in the World's population

The NYT article published the following graph (describing the prospective path of the World's population) that pretty much said it all.



demographics, population decline, Marin County, Italy, Japan