Population Projections

[Desert Mariner]

Dragoon500ly’s thread on population increase/decrease got me looking at my old population projection spreadsheet and I realized that it was long overdue for an update. For those interested the result is attached.

As opposed to previous versions of this tool, this one calculates the Base Population rather than just using the most recent census figures. So, if your TEOTWAWKI is in 1987, the spreadsheet takes the 1980 census figures and applies growth through 1987 to arrive at your base population.

I’ve also added the Canadian Provinces using Canadian data from 1971, 1981, 1991, 2001 and 2011 with US data for 1970, 1980, 1990, 2000 and 2010 respectively. 2020 figures are projections from the University of Virginia for the States and 2016 census figures for the Provinces. [Note: The province of Nunavut was a part of NW Territories until 1999 so it will display a population of 0 prior to 2000]

There are three (3) worksheets in the file:
Input – Enter your parameters
• TEOWAWKI Year – Allowable entries are 1970 through 2019 inclusive.
• Growth Rate [Die-Off & 1-10] – Enter the percent change (may be negative) in population for each period. This figure is applied annually for the duration of the corresponding time period and includes births, mortality and migration.
• Time (Years) [Die-Off & 1-10] – Enter the length of time the corresponding Growth Rate should be applied. Time for Die-Off should always by 1.
If you leave the Growth Rate blank, no results are shown in the Projection tab for that and all subsequent periods (i.e. if Period 4 is blank then no results will display in Periods 4-10).
Projection – Displays your results. The calculated year is displayed at the top of each Period column.
Places – Background tables with census information for each state and province.

Projection formula: Pt = P0 * (R+1)to the power of T

Where:

P0 = Base population
Pt = Projected population
R = Growth Rate
T = Time

Any comments and/or feedback are appreciated.

[mmartin798]

Originally Posted by Desert Mariner

Dragoon500ly’s thread on population increase/decrease got me looking at my old population projection spreadsheet and I realized that it was long overdue for an update. For those interested the result is attached.

.
.
.


Any comments and/or feedback are appreciated.

There is a problem with your base population calculation. You are using the percent change over the decade as the growth rate. They are not the same thing. The error is most obvious in the spreadsheet for Florida which shows a base population over 70 million in 1988, when the 1990 census data shows a population of only 9 million.

Since you have the census data, you could just do interpolation to get a much closer estimate for the base populations.

[Desert Mariner]

Originally Posted by mmartin798

There is a problem with your base population calculation. You are using the percent change over the decade as the growth rate.

Thanks for pointing out the error. The issue was actually in the growth rate table. Something was off when I copied from the original. It's now been fixed (constants replaced with the original formulas) and the calculations appear to be functioning as intended.

Corrected file is attached. If you see anything else, please be sure to let me know.

[Desert Mariner]

I'm in the process of updating this generator with US 2020 census figures. If anyone is interested, I can post it when I'm finished.