Wednesday, March 06, 2019

Where Olympia has lost population

When you think about population change in a growing region, you think of it as a constant. And, even though Olympia has been lagging behind Lacey in growth rate for the past few decades, Olympia is still on a gradual population climb.

But, that population growth has not been consistently spread across the city. In fact, there are numerous neighborhoods that have actually lost a significant amount population in recent years.

To explore this phenomenon, I built a map in a tool called Policy Map. The variable I used was the rate of change in the five years between 2013 and 2017, according to the American Community Survey. These are interesting years because it was a time when the incoming population of our area outpaced new housing. So, at least in theory, our available housing became more crowded, not less.

A small caveat about this data. It is based on survey results collected by the Census Bureau. Being survey results it is less accurate than actual decadal census data. That said, all of these neighborhoods have seen measured losses of over 13 percent, which would probably outstrip any margin of error.

The first neighborhood in Olympia that lost a significant amount of population (again, more than 13.46 percent) was this one up in far northeast Olympia.


This Lilly to Southbay Road neighborhood is the outlier in the type of neighborhood that has lost population though. The much more typical neighborhood (in dark brown below) is an older, inner residential neighborhood.


Here's the map key:

I've written about these neighborhoods before and in my mind, these are the neighborhoods that beginning in the late 1970s started seeing the impacts of growth cascading out of downtown. They experienced an influx of what we now call "missing middle" housing, multiplexes and small apartment buildings. But, instead of welcoming the growth and naturally more dense neighborhoods, these neighborhoods downzoned and pushed additional growth towards the edges of town. This new growth, in turn, paved over farms and forests.


But, why now are these neighborhoods that up until a few months ago were protected habitat for single-family homes losing population? Obviously, the neighborhoods weren't becoming denser. I'm having a hard time finding data on the change in household size in the same year, but it stands to reason that stable households would have children age out eventually. If the parents stayed put, then theoretically, the population would decline. 

1 comment:

TVDinner said...

Emmett, I really hope you’re looking at the margins of error on that ACS data. My experience with the ACS at the small geographies you’re showing is that even the 5 year estimates are just statistical noise for the populations you’re looking at. I don’t think you can responsibly draw any conclusions from it.

+1 on the new mapping software. Those Google maps with pins were pretty tough to read!