Something different …
Here is a look at the last 50 to 60 years, and some predictions about the next 50+ years.
First, here is a graph from the Census Bureau showing the Median Center of Population for the United States: 1880 to 2020
From 1880 to 1950, the median center of the US population bounced around the border between Ohio and Indiana. And then the median center started moving southwest.
A key driver of the westward movement was the availability of water, and this boosted population growth in California, and in several other states like Arizona, and Nevada. The population California increased 150% from 1960 to 2020, and Arizona’s population increased more than five-fold. Nevada’s population increased more than ten-fold! (For comparison, the US population increased 85% from 1960 to 2020).
The key driver of the southward movement was Air Conditioning! AC has made the Southern States and D.C. more habitable year-round (Arizona and Nevada benefited from both additional water supply and AC).
From the Census Bureau Population Shift to the West and South (emphasis added).
The 100th meridian generally defines the boundary between the humid eastern and arid western parts of the United States. Historically, living west of the 100th meridian has meant a reliance on irrigation for successful agriculture and substantial settlements were limited in size. The 38th parallel divides the country based on average July temperature, with most of the country below the parallel experiencing average July temperatures of over 80 degrees. The completion of large-scale dam projects in the early 20th century generated water and electricity that made it possible for large cities to develop in the West. The widespread use of air conditioning after the 1970s helped make living in hotter parts of the country more tolerable.
The Census Bureau also has a great interactive chart showing the shift in population from 1790 to 2020.
AC: From Luxury Item to Must Have
The following graph shows single-family homes completed with Air Conditioning since 1973 by region. The South has been close to 100% for several decades, and the rest of the country is catching up. According to the 2021 American Housing Survey (AHS), 92% of all US homes now have AC (either primary or room AC).
If you were a home builder 50 years ago, you’d start concentrating on building in the West and all across the South to take advantage of this shift.
But what about the next 50 years?
The Next 50 Years for Housing and Population
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