Accuracy is crucial in a population projection. It allows governments and other institutions to plan wisely and helps individuals comprehend the likely futures for their countries and the world. Yet there are no prizes for accuracy, and forecasters seldom have the satisfaction of appreciating their success. The projections we consider are so long term, covering several decades, that before they can come true — or be proven false — the forecasters themselves are likely to have been swallowed up by demographic processes: if not mortality or migration, then certainly job mobility.
— from “Beyond Six Billion: Forecasting the World’s Population; Chapter 2: The Uncertainty of Population Forecasts” by the National Academies Press, 2000.
Following the approval of two community-centered proclamations, the first order of business at the Tuesday, March 19, Archuleta Board of County Commissioners meeting was to allow public comment from the audience. I was the first person to step up to the microphone.
I wanted to express some concerns I have about the way our local governments have been using “population forecasts.” We’ve seen some pretty inaccurate forecasts embraced by certain agencies here, and that includes estimates done by the Colorado State Demographer’s Office — folks who make their living forecasting populations, but who have consistently missed the mark by a significant margin in Archuleta County.
According to an article on the National Academies of Science, Engineering, and Medicine website, population forecasts are always subject to errors, and the errors become compounded the further out the forecaster tries to predict. Here’s the article I was reading last weekend. It’s 348 pages long, and I didn’t come close to reading the entire article.
But what I did read got me thinking: How would a forecaster do the very best job of projecting future populations?
The National Academies article was focused on projections of the global population, which is certainly more complicated — exponentially more complicated — than predicting a future population for Archuleta County. But let’s think about what factors might be considered, in producing a scientifically valid population projection for our little community.
Here is a partial list:
- Number of women of childbearing age, and fertility rate trends
- Incoming and outgoing migration trends
- Ages of current residents and likely ages of future residents
- Number of homes and potential homesites in the community, and their prices
- Employment trends, including wages and number of potential employers
- Trends regarding real estate purchases by second home buyers and investors
- Development costs for new housing and businesses
- Government and business spending trends
These are a few of the factors that a professional forecaster might consider.
For example, a large in-migration of 25-year-olds — ready to start young families — could have a very different long-term effect on a community population, than would a large influx of 65-year-old retirees. The 25-year-olds and their children might stick around for 60 years. The 65-year-olds would not be around for that length of time.
Conversely, a community-wide housing crisis might generate a significant out-migration of 25-year-olds, but might have little effect on 65-year-old retirees.
When I moved to Pagosa Springs in 1993, the median age was around 37 years. As of 2018, the US Census estimated the median age at 50 years, with 24 percent of the population being 65 or older. How many of those same 65-year-olds will still be here in 2050? Not too many, I suspect.
We could also look at land use trends. If the most buildable lots in a community already have homes on them, then future homes — built on more challenging terrain — will be more expensive in comparison, and that fact would limit the type of people who can afford to locate in the community.
Which brings us back to the Growing Water Smart Work Group population forecast, produced by Gabe Preston of Durango-based RPI Consulting. The BOCC and several other agencies paid for Mr. Preston’s forecasting work — but, according to the data provided to the Work Group last month, RPI did not look very closely at the trends I mentioned above. (You can download a 29-page summary of the RPI data here.)
What RPI eventually focused on was, basically, this: How much did the Archuleta County population grow between 2000 and 2018? If the growth trend remained the same for the next 30 years, what would the population be in 2050?
A pretty simple approach.
From what I can tell, RPI did not look at fertility rates, or land use trends, or employment trends, or economic trends, or home ownership trends, or migration trends. They could have seriously studied those trends, but didn’t, for whatever reason.
Nor have our local governments been looking at such trends, from what I can tell, except in the most cursory manner. The typical “economic development” efforts funded by our local governments — and to a lesser degree, by our local businesses — seem to have been based on the following assumptions:
- An increase in population will benefit the community.
- It makes no difference who moves into the community, so long as the population is increasing.
- Rising real estate prices are the sign of a healthy economy.
- If the community grows, the number of jobs will grow, and young people will locate here to fill those jobs, regardless of rental rates and housing costs.
As the National Academies Press noted in their “Beyond Six Billion” report, accuracy is critical in a population projection, because government and business leaders will probably not look very closely at the data behind the projection, but will instead assume that it was done accurately. They will then schedule expenditures and investments based on those projections.
Over the past few weeks, the Archuleta BOCC has been making plans to lay a $13 million debt onto the shoulders of the community’s taxpayers — $20 million, when you include the interest payments — to build a 54-bed jail. The average number of daily inmates housed by the Archuleta County Sheriff, between 2010 and 2018, was less than 20. But our three-member BOCC believes that population growth is inevitable, and that the very best investment they can make on our behalf, in 2019, is a big, new jail.
A better investment than fixing our roads, apparently.