Population Growth Patterns in Metro Areas, 2000-16

[cinyc]

Metro Louisville:

[cinyc]

Richmond:

[cinyc]

Hartford:



It used to grow, but not so much any more.

[cinyc]

The Salt Lake City Metro - which is technically just Salt Lake County and the geographically huge but sparsely populated Tooele County.  I've expanded the map a little to get in more Wasatch Front cities that are in the CSA but not metro area.

[cinyc]

Greater Birmingham, Alabama:

[cinyc]

The Buffalo Metropolitan area, which is just Erie and Niagara Counties:



Buffalo and Niagara Falls lost a lot of population.  Only some of that loss was made up in the suburbs - but at least Buffalo's suburbs and exurbs have been slightly growing.

Buffalo rounds out the top 50 metros - only 3 more metros with a population over 1,000,000 remain.  After I am done with those 3, I'm probably going to have to go back to properly frame some of the earlier metro areas to include all counties.  And, as always, I'll take lower-ranking metros on request.

[cinyc]

Rochester, NY:

[cinyc]

The growing Grand Rapids, Michigan metropolitan area:

[cinyc]

And last (at least for now), one of the least interesting maps I've made so far - the Tucson Metro Area, which is just Pima County:

[cinyc]

For comparisons, here's a map of NYC Metro Growth from 2000-10 and 2010-16 (versus the April 2000 and 2010 estimates base) and the NYC yearly growth gif.  These maps isolate out the NYC metro from the rest of the country.








Note that the key for the static multi-year change maps is in 2-point increments, and I haven't reframed the gif to get the outer areas of Dutchess and Ocean Counties in yet.

[jimrtex]

Is this plausible enough to be used for a reliable projection to 2020, for purposes of redistricting?



The holes on the map along the Schuylkill and around the Naval Shipyard are very small census tracts. The change ranges from 20% to -20%, from the 2010 Census to the 2015 5-year ACS (which would represent an averaged population from 2011 to 2015), if the rate of change were constant, this would be about July 2013.

[cinyc]

Is this plausible enough to be used for a reliable projection to 2020, for purposes of redistricting?



The holes on the map along the Schuylkill and around the Naval Shipyard are very small census tracts. The change ranges from 20% to -20%, from the 2010 Census to the 2015 5-year ACS (which would represent an averaged population from 2011 to 2015), if the rate of change were constant, this would be about July 2013.

What would you do?  Triple the rate from the ACS?

I think there's an issue with post-recession rates of change being different than pre-recession rates.  For example, the Pittsburgh region seems to have actually grown a bit from 2008 to 2012 or so - and has declined since.

[jimrtex]

Is this plausible enough to be used for a reliable projection to 2020, for purposes of redistricting?



The holes on the map along the Schuylkill and around the Naval Shipyard are very small census tracts. The change ranges from 20% to -20%, from the 2010 Census to the 2015 5-year ACS (which would represent an averaged population from 2011 to 2015), if the rate of change were constant, this would be about July 2013.

What would you do?  Triple the rate from the ACS?

I think there's an issue with post-recession rates of change being different than pre-recession rates.  For example, the Pittsburgh region seems to have actually grown a bit from 2008 to 2012 or so - and has declined since.

What I did for the county projections is determine the annual rate of increase from 2010-April to 2016-July, and project that forward to 2020. For county subdivision projections in Allegheny, Chester, and Montgomery, I did the same, but controlled the total population for a county to the 2020 county estimate.

The rate of increase in the estimates for Philadelphia have definitely slowed over the past 3 years, so that I am over projecting assuming that the rate for the remainder of the decade remains low(er).

What I have decided to do for Philadelphia is to aggregate the populations of the census tracts assigned to each district for the 2010 census and the 2011-2015 ACS, determine the percentage change, and then assuming that the 2011-2015 population is a July 2013 population, determine an annual rate of increase, project that to 2020, and then control to the 2020 county estimate.

So far, I've done the trans-Schuylkill. Initially the population was down based on the areas closer to the shipyard, but there is now an increase as I've got further west (Temple area?).

[cinyc]

I'm working on a larger project with more historical maps.  For now, here's a gif of percentage population growth in the US from 1900-2016, using 2016 county lines throughout:



Numerical Change Map, for comparison:


Alaska (From 1960):


Hawaii:


Unlike Alaska, Hawaii's data goes back pre-statehood.  

In case you can't read the key, color gradation is in 5-point increments from 0-60%. Gold colored counties didn't exist in those years.  Usually, they were part of another county.

[jimrtex]

I'm working on a larger project with more historical maps.  For now, here's a gif of percentage population growth in the US from 1900-2016, using 2016 county lines throughout:

The 1920-1930 blue swath across Georgia was interesting. Reprise of Sherman's march to the sea?

[Brittain33]

Great migration, I wonder?

[cinyc]

The 1920-1930 blue swath across Georgia was interesting. Reprise of Sherman's march to the sea?

According to the Georgia Enyclopedia, the boll weevil decimated the cotton crop, leading to a mass exodus from the state's cotton belt: "During the 1920s more than 400,000 residents, almost all black, migrated to other parts of the country, and between 1910 and 1930 nearly half the state's agricultural workers had abandoned farming."