HomeMy WebLinkAboutDemographic Trends in the Bozeman and Belgrade School DistrictsDemographic Trends in the Bozeman and Belgrade School Districts
Prepared by Gallatin County GIS for the Planning Coordination Committee (PCC) Meeting held
on June 14th, 2023 from 11:30 – 13:00
1
Introduction
The question under consideration is whether there is a corresponding increase in school enrollments
with the increase in the general population of the Bozeman and Belgrade School Districts. A first step in
answering this question is to establish what we really mean by the question. A one-to-one
correspondence can graphically be understood as two parallel lines increasing at the same rate (see
Figure 1). This can be numerically represented as identical growth rates where the growth rate is
determined by the formula below. 𝑃𝑃𝑃𝑃𝑃𝑃𝑃𝑃𝑃𝑃𝑃𝑃𝑃𝑃𝑃𝑃𝑃𝑃𝑃𝑃2 −𝑃𝑃𝑃𝑃𝑃𝑃𝑃𝑃𝑃𝑃𝑃𝑃𝑃𝑃𝑃𝑃𝑃𝑃𝑃𝑃1𝑃𝑃𝑃𝑃𝑃𝑃𝑃𝑃𝑃𝑃𝑃𝑃𝑃𝑃𝑃𝑃𝑃𝑃𝑃𝑃1
Figure 1. Comparing demographic trends visually
The criteria for corresponding growth between the general population and school district enrollment
should look like correspondence in Figure 1, above, and it should be numerically represented by
identical growth rates. If it is the case that the rate of school enrollment corresponds with the general
population growth, then we should see similar or near-similar rates of growth. This will be understood
as what is meant by the question at hand for the purposes of this report. Alternatively, we can
understand population and enrollment trends as diverging or converging as graphically shown in Figure
1. The former is represented numerically by a higher growth rate for one population and a lower for the
other. The latter is represented numerically by the inverse comparative relation.1 This brief report aims
to answer the question of correspondence while also providing an exploration of the resulting
information.
Data and Methods
The geography chosen for examination was based on the Planning Coordination Committee (PCC)
boundary but extends beyond that boundary to capture the relevant school districts. The geographic
area is composed of the Belgrade and Bozeman High School districts which contains the Bozeman,
Monforton, and Belgrade elementary districts within (see Attachment I). It is difficult to get detailed,
fine grain data for relatively rural geographies like the area under consideration. Fortunately, census
block data with population counts were available for the 1990, 2000, 2010, and 2020 decennial
censuses. These datasets provided two age breakdown categories, 18 and older and under 18, along
1 These graphic patterns can convey old-age dependency and child dependency if one population is persons aged 65+ and the other population
is persons aged 0-14, respectively.
2
with total population counts. These are the most accurate age and population datasets available. Only
the census blocks contained within the Belgrade and Bozeman HS districts were chosen for this analysis
and the match of the boundaries is near perfect except for the 1990 census blocks which varied
significantly (see Attachment II). The boundaries of both high school districts were used to select the
subset of census blocks used to calculate only the populations within those geographies. This data
provides the total population, 18 and over, and under 18 population figures used in the results of this
report.
Enrollment data from the Montana Office of Public Instruction (OPI) was requested going back to 1990
but the data provided only went back to 2008. Another dataset was available from the Montana State
Library (MSL) and covers 1987 to 2021. There are some unexplained discrepancies in the two data
sources for the years they have in common but the MSL data was chosen for this report since it covered
the desired timeline. Combined, the selected census block population data and school enrollment data
will provide the data needed to answer the correspondence question.
Two additional datasets were acquired to from the 2010 and 2020 American Communities Survey (ACS)
for the Bozeman and Belgrade high school districts to provide figures on the median age and age
dependency ratios. These figures will provide some insight into changes in age groups within the
populations of these respective geographies over the past decade. Finally, age distribution data was
acquired from the 2020 Census for the Bozeman and Belgrade high school districts to create population
pyramid graphics for the two respective geographies. These supplemental datasets will help guide any
further exploration of demographic trends and provide insight into some further questions.
Results and Discussion
Figures 2 and 3, below, display two categorical population counts and total primary and secondary
school enrollments for the Bozeman and Belgrade high school district (HSD) geographies. The table in
Attachment III provides the growth rates for the same figures and geographies. Both graphs display a
divergent population trend with the population 18 and over increasing at a much higher rate than both
school enrollment and the population of under 18. The population of adults (=>18 years old) for the
Bozeman HSD geography increased at a rate of 134% over the 40-year period while the population of
children only increased at a rate of 79% over the same period with total school enrollments trailing
0
10000
20000
30000
40000
50000
60000
70000
1990 2000 2010 2020
Bozeman HS District Population and Enrollment Trends from
1990 to 2020
Population 18 and Over Population Under 18 Total School Enrollments
Figure 2. Bozeman HS district geography results
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behind at 69%. This means that there is no corresponding growth of enrollments to the growth of the
general population over the entire period for the Bozeman HSD geography.
The Belgrade HSD geography demonstrates a divergent trend pattern but slightly less pronounced than
that of Bozeman’s due to the widening of the gap between 2010 and 2020. The population of adults
(=>18 years old) for the Belgrade HSD geography increased at a rate of 256% over the 40-year period
while the population of children only increased at a rate of 142% over the same period with total school
enrollments trailing behind at 121%. This means that there is no corresponding growth of enrollments to
the growth of the general population over the entire period for the Belgrade HSD geography.
Table 1. Comparison of Age Group Trends within the Belgrade and Bozeman HS Districts from 2010 to 2020
Belgrade HS District Bozeman HS District
2010 2020 2010 2020
Median age (years) 31.9 35.2 30.8 30.9
Age dependency ratio2 52.8 60.7 36 41.1
Old-Age dependency ratio3 9.4 17.4 12.2 17.1
Child dependency ratio4 43.4 43.3 23.8 24
Table 1, above, reinforces the trend displayed in Figures 2 and 3. The median age is increasing along
with all the dependency ratios except for the child dependency ratio for Belgrade HSD. All these
2 The dependency ratio is a core demographic and economic indicator that relates the number of children aged 0-
14 and older persons (65 and over) to the working-age population (15-64). A higher age dependency ratio means
those of working age, and the overall economy, face a greater burden in supporting the youth and the elderly.
3 The old-age dependency ratio is a disaggregated metric from the age dependency ratio that only looks at persons
aged 65 and older. Higher ratios indicate higher levels of elderly care dependency on a smaller working aged
population. 4 The child dependency ration is a disaggregated metric from the age dependency ration that only looks at children
aged 0-14. Higher ratios indicate higher levels of childcare dependency on a smaller working aged population.
0
5000
10000
15000
20000
1990 2000 2010 2020
Belgrade HS District Population and Enrollment Trends from
1990 to 2020
Population 18 and Over Population Under 18 Total School Enrollments
Figure 3. Belgrade HS district geography results
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indicators point to an increasingly older population in both geographies. The population pyramids in
Figures 4 and 5 demonstrate how the population is distributed by age groups in both geographies as of
the 2020 Census. This provides a recent snapshot of where both HSDs stand and compare.
Figure 4. Bozeman HSD Population Pyramid
20 15 10 5 0 5 10 15 20
>5
5 - 9
10 - 14
15 - 19
20 - 24
25 - 29
30 - 34
35 - 39
40 - 44
45 - 49
50 - 54
55 - 59
60 - 64
65 - 69
70 - 74
75 - 79
80 - 84
>=85
Percent
2020 Census Population Pyramid for Bozeman HS District
Male Female
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Figure 5. Belgrade HSD Population Pyramid
A population pyramid should be shaped like a pyramid when there is a growing population with the
lower age groups at the base making up a larger proportion of the population. Neither the Bozeman nor
Belgrade HSD geographies display a population pyramid of growth. Rather, both display an aging
population with a top-heavy formation. This corresponds with all the data presented.
Conclusion and Reflection
The relationship between the general population and school enrollments is divergent rather than
corresponding. This means that the population of adults is far outpacing the population of children in
both HSD geographies. More specifically, it has been shown that the population is increasing at a higher
rate with older adults through metrics like the age-dependency ratio. This suggests that the main driver
10 8 6 4 2 0 2 4 6 8 10
>5
5 - 9
10 - 14
15 - 19
20 - 24
25 - 29
30 - 34
35 - 39
40 - 44
45 - 49
50 - 54
55 - 59
60 - 64
65 - 69
70 - 74
75 - 79
80 - 84
>=85
Percent
2020 Census Population Pyramid for Belgrade HS District
Male Female
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of population change in both HSD geographies is in-migration of older adults. This is a general trend that
is now well understood in the academic literature of the geography and demography of the inter-
mountain west. In the, now outdated, seminal work of William R. Travis’s New Geographies of the
American West5, he writes the following:
The ‘wealth effect’ of the 1990s economic and stock market boom had people who were
backpacking in the Wind River range during the 1970s now buying condos at ski areas or houses
on golf courses, spending time in developed resort areas instead of in the backcountry. This
resort real estate boom did not slow with the economy in the early 2000s; all-time real estate
sales records were set in 2005 in classic resorts such as Vail and Aspen. The second-home boom
is a national phenomenon, likely to grow even larger as baby boomers move into the prime
resort real estate buying age, pegged at 55-64 years by a recent study.
Dramatic increases in investment, real estate appreciation, and demand for services have
induced and affordable housing crisis in most resorts. Rising prices have forced many workers to
live farther and farther from the resort town proper, creating an enlarging sphere of resort
influence, now taking in the entire subregions of growing bedroom towns. Inevitably, the resorts
themselves have also sprawled, not only because workers have moved farther out for cheaper
housing but also because the resort boom itself could not be contained by the pinched
geography common to many resort towns… the resorts therefore, present a three-part
geography:
1. The core resort, and adjacent facilities such as ski areas and golf courses;
2. The staging areas (and the roads and highways that link them to the resort), in outlying
towns and rural areas, to which many resort workers as well as commercial land uses that
don’t suit resort style (e.g. self-storage facilities; roofing, plumbing, and landscaping
companies) are banished;
3. A sprawling amenity zone, something like an exurb, including high-end residential
developments (often large-lot, large-house second-home developments), outlying golf
courses, fishing properties, and more and more, trophy ranches. In places this zone
envelops the towns of the staging area, thus raising their real estate prices, too.
The center-periphery geographic story laid out in the above excerpt articulates a relationship between
the City of Bozeman and the surrounding communities. Although this brief report has only explored the
demographic trends of the Bozeman and Belgrade region, it fails to provide much in the way of
explaining the why and how of the trends presented. Travis’ narrative helps set a course for finding
those answers in the socio-economics associated with the different age groups. It is beyond the scope of
this report to explore those issues but it is clear that the wealth distribution among age groups is a place
to look along with the general effects of amenity migration on the ability of working-aged people to
start families within amenity communities (e.g. there’s an “amenity penalty” for working persons living
in amenity communities where the compensation for a given job is well below the national average for
the same job while the cost of living is far higher). Diving further into smaller geographies and
comparing the demographic differences between individual schools may also provide more insight. For
5 Travis William R. New Geographies of the American West: Land Use and the Changing Patterns of Place. Island
Press 2007. (pg. 145-146)
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example, a question to ask would be: are schools within or around districts that allow vacation rentals
seeing disproportionately fewer students? Examining such a question is warranted given the well-
understood geography of amenity communities and their socio-economic impacts.
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Attachment I
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Attachment II
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Attachment III
Table 2. HS District Population and Enrollment
Categories Decennial Census Absolute Change % Change 40 Year Period
1990 2000 2010 2020 1990 to 2000 2000 to 2010 2010 to 2020 1990 to 2000 2000 to 2010 2010 to 2020 Abs Change % Change Belgrade Pop. Total 7922 12675 20155 25212 4753 7480 5057 60% 59% 25% 17290 218%
Pop. >=18 5303 9052 14482 18869 3749 5430 4387 71% 60% 30% 13566 256%
Pop. <18 2619 3623 5673 6343 1004 2050 670 38% 57% 12% 3724 142%
Total Enrollment 1569 2155 2986 3461 586 831 475 37% 39% 16% 1892 121%
Belgrade ED 1189 1434 2134 2459 245 700 325 21% 49% 15% 1270 107%
Belgrade HSD 380 721 852 1002 341 131 150 90% 18% 18% 622 164% Bozeman Pop. Total 35680 45487 57757 79285 9807 12270 21528 27% 27% 37% 43605 122%
Pop. >=18 27941 36692 47296 65421 8751 10604 18125 31% 29% 38% 37480 134%
Pop. <18 7739 8795 10461 13864 1056 1666 3403 14% 19% 33% 6125 79%
Total Enrollment 4568 5298 5838 7733 730 540 1895 16% 10% 32% 3165 69%
Bozeman ED 3099 3252 3705 4851 153 453 1146 5% 14% 31% 1752 57%
Bozeman HSD 1266 1843 1948 2260 577 105 312 46% 6% 16% 994 79%
Monforton ED 203 203 185 622 0 -18 437 0% -9% 236% 419 206%