Derek Dauphin USP 535 – Methods II Assignment 5 – Population and Employment Analysis Multnomah County and Washington County hold most of the Portland Metro region’s population. The former is the historic center of urban development, while the latter is home to the newer and faster growing cities of Beaverton and Hillsboro. Multnomah is known for manufacturing, marketing, and software development. Washington is the center of the so-‐called “Silicon Forrest” with computer component manufacturers such as Tektronix, Intel, HP, and Xerox. I have used certified population estimates provided by the PSU Population Research Center (PRC) along with data from the Bureau of Labor Statistics (BLS) to look at how these two areas have changed in the last 10 years. Overview of Multnomah and Washington County Populations In the last 20 years, as the US population grew 24.1%, and Oregon State grew 35.2%, the population of Washington County grew 71%, adding 221,066 people in 10 years (Table 1). Multnomah County’s growth was in line with national averages at 25%, adding 146,253 residents since 1990. Most of this growth occurred before 2000, with the state population increasing half as much in the 2000s as it did in the previous decade, and Washington County growing by even less. Multnomah County, on the other hand, grew only slightly less in the 2000s over 1990s levels. In 2008, both counties had a higher share of their populations between the ages of 25 and 49 than in the rest of the state, 38% and 39.3% for Washington and Multnomah Counties, respectively, compared to 35% for the state (Figure 1 & Table 1). As expected, suburban Washington County had a much larger share of its population under the age of 14 (22.5%) than urban Multnomah County (18.7%). The counties showed a higher share of male residents between the ages of 35 and 49 than the state, and a higher share of females from the age of 65 (Figure 2). This information is important to many areas of planning. Young people have children that need to go to schools and who may have migrated from the central city to the suburbs to buy homes. Homes, schools, and the infrastructure connecting them with their community will need to be provided. Understanding where the elderly population is living is important not only for housing issues, but also for walkability and transit agencies. Population Forecasts for the Year 2020 Using data from the last 20 years, we can extrapolate population growth to 2020 using three methods: Linear growth, Average Annual Absolute Change (AAAC), and Average Annual Percent Change (AAPC). The linear model assumes growth follows a linear pattern that can be found by calculating a trend line from historic data. The line’s equation is used to extrapolate future population. 1990-‐2010 PRC data was used to establish a trend line resulting in a 2020 projection of 4,330,045 residents in Oregon State (12.3% growth), 798,651 in Multnomah County (9.4% growth), and 640,970 in Washington County (20.3% growth) (Table 2 & Figure 3). These increases are close to those observed between 2000 and 2010, indicating the influence of these data points in the projection over the higher projections that would result if the trend line were based on the rapid expansion of the 1990s (Table 1). The AAAC model takes population differences between two points in time and divides that by the number of years intervening, ignoring trends between these two points. For this reason two sets of years have been used with different starting or “baseline” years: 1990 and 2000. For both estimates, the end year was 2010. Resultant AAAC values were applied for each successive year to extrapolate 2020 estimates (Table 2). Our 1990 baseline AAAC estimates are very similar to our linear projections because they are both linear models using the same period of time, with the only difference being that the linear model incorporates the intervening data. The AAPC model is based on establishing a geometric growth rate, again using baseline and end years. This rate is used to estimate the 2020 population (See Table 2 for estimates). Because this method increases the population by a percentage each year, it generates a curved line resulting in higher estimates than linear and AAAC methods.
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For all projection methods, 1990 baseline results are consistently higher than 2000 estimates due to the rapid population growth of 1990s. This may be more accurate if the area returns to this level of growth, or it may be grossly inaccurate if the current level of growth continues into the next decade. To determine which baseline is best, we must understand what caused the expansion of the 1990s and determine if those conditions will be present in the decade to come. Historic trends show non-‐geometric growth even in the 1990s and so using the AAPC is not advised for these regions. For planners, high levels of population growth may be the result of successful economic initiatives. In addition to the need for development discussed above, those involved with food, energy or other resources must respond to the potential for scarcity. Computer Systems Jobs and Wages Between 2001 and 2010, BLS data shows the number of private sector jobs in all industries went down for the nation (2.8%), the state (1.9%), and Multnomah County (7.9%). In Washington County they have gone up (0.1%) (Table 3). While Multnomah County and the state have seen stagnant wages, Washington County’s wages have grown faster than the national rate. In 2001, Washington County residents made an average of $6,940 more each year than residents of Multnomah County, an earning gap that grew to $9,324 in 2010. Is this growth in jobs and wages in Washington County due to the high number of Computer Systems companies located there? The short answer appears to be no. The data shows that even though overall job numbers have slightly risen in Washington County, they have lost 19.6% of the Computer Systems jobs they had in 2001 (Table 4). While Multnomah County lost a larger proportion of its computing systems jobs (24.8%), its wages have risen 4.4% -‐-‐ higher than the state (1.6%) or the nation (0.8%) for this sector. Washington County has lost jobs and wages have gone down 1.5% from 2001 levels. These numbers are surprising as the nation saw a 13.1% increase in these jobs and a 0.8% increase in wages in this sector. A location quotient (LQ) is a ratio of the percent of employment due to a particular industry in a local economy compared that of the state or national economy. Multnomah County’s LQ relative to the state stayed at 1.0 between 2001 and 2010, while its LQ relative to the nation dropped from 0.7 to 0.5. In 2001, Washington County had nearly twice as many of its jobs in the Computer Systems sector than the state (LQ=1.8) which did not change substantially in 2010 (LQ=1.7). However, while in 2001, the county had 30% more Computing Systems jobs than the nation (LQ=1.3), by 2010 the LQ dropped to 0.9. This means the state’s share dropped at about the same rate as the county, but both dropped compared to the nation. More information about the industry and where these jobs are being lost and from which companies would help explain this phenomenon. Washington County’s LQ is not going down because it is diversifying its jobs market, this is due to actual job loss (Figure 4). The final measure we will look at is a shift-‐share analysis, which measures differences in the growth of local and state/national economies. It requires the calculation of a national share (NS) measuring trends in the large economy, the industrial mix (IM) showing the changes due trends in the industry, and the local factors (LF) unique to our region of interest. Breaking the 805 jobs lost in Multnomah County between 2001 and 2010 shows us that only 92 of these jobs were lost due to national employment trends (NS=-‐92), and that the county should have added 518 jobs due to trends in the industry (IM = 518). The local factor for the county shows a true loss of 1,231 jobs (LF=-‐1,231). Multnomah County could have lost many more jobs in this sector if not for outside factors. Values for Washington County show the same picture (NS=-‐94, IM=527, and LF=-‐1,082). Much more information is required about the businesses in the two counties and across the state to understand what is causing such local contraction of a sector that appears to be growing nationally. For planners, economic growth leads to new building and more tax funds for projects to improve cities and regions. Economic contraction results in the opposite trends and the often discussed “shrinking city” phenomenon that has placed great stress on municipal planning departments. Economics are also part of the analysis that helps us determine which methods best estimate future population to ensure infrastructure and other services match future demands.
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Table 1: Population Change and Age – US, Oregon, Multnomah County, and Washington County, 1990-‐2010
United States
Population (count)
Multnomah County
Oregon State
Washington County
1990
248,709,873
2,842,337
583,887
311,554
2000
281,421,906
3,436,750
662,400
449,250
2010
308,745,537
3,844,195
730,140
532,620
32,712,033
594,413
78,513
137,696
13.2
20.9
13.4
44.2
27,323,631
407,445
67,740
83,370
Population change 1990-‐2000 (count) 1990-‐2000 (%) 2000-‐2010 (count)
9.7
11.9
10.2
18.6
60,035,664
1,001,858
146,253
221,066
24.1
35.2
25.0
71.0
Under 14
N/A
19.3
18.7
22.5
15-‐24
N/A
13.6
12.4
13.0
25-‐29
N/A
6.9
7.8
7.3
30-‐54
N/A
35.0
39.3
38.0
Over 55
N/A
25.2
21.8
19.3
2000-‐2010 (%) 1990-‐2010 (count) 1990-‐2010 (%) Population by age (%)
Source: US data from HUD State of the Cities Data Systems (SOCDS); State and county data for 1990 and 2010 from US Census, 2000 population from PSU PRC certified estimates. Note: “Population by age” is the percent of each political region’s total population that is within that age range.
Table 2: Comparison of Population Projections for 2020 – Oregon, Multnomah County, Washington County
Multnomah County
Washington County
Estimate
Oregon State % Increase
Estimate
% Increase
Estimate
% Increase
AAAC, 1990 baseline
4,345,124
13.0
803,267
10.0
643,153
20.8
AAAC, 2000 baseline
4,251,640
10.6
797,880
9.3
615,990
15.7
Method
Difference
93,484
2.4
5,387
0.7
27,163
5.1
AAPC, 1990 baseline
4,470,646
16.3
816,479
11.8
696,401
30.8
AAPC, 2000 baseline
4,299,945
11.9
804,807
10.2
631,461
18.6
170,702
4.4
11,671
1.6
64,940
12.2
4,330,045
12.6
798,651
9.4
640,970
20.3
4,339,480
12.9
804,217
10.1
645,595
21.2
Difference Linear, adjusted Mean of all estimates
Baseline data source: 1990 and 2010 from US Census, 2000 population from PSU PRC certified estimates.
Note: “`% Increase” measures how much the projection shows the population increasing from the 2010 count. “Linear, adjusted” values are extrapolated using the equation of the trend line, and then “adjusted” by adding/subtracting the difference between the model’s projected 2010 population and the actual population.
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Table 3: All Private Sector Industry Jobs and Average Annual Wages (in 2010 Inflation Adjusted USD) – US, Oregon, Multnomah County, Washington County, 2001 and 2010
United States
Jobs (count)
Multnomah County
Oregon State
Washington County
2001
109,304,802
1,343,240
380,379
211,936
2010
106,201,232
1,318,288
350,418
212,152
-‐2.8
-‐1.9
-‐7.9
0.1
Change (%) Wages (USD)
2001
44,473
40,283
45,694
52,534
2010
46,455
40,984
45,765
55,089
4.5
1.7
0.2
4.9
Change (%)
Source: Bureau of Labor Statistics Quarterly Census and Employment Wages. Notes: Private sector data included for all industries. A Consumer Price Index (CPI) of 1.23 was used to adjust 2001 dollars to 2010 levels due to inflation.
Table 4: Computer Systems Jobs and Average Annual Wages (in 2010 Inflation Adjusted USD) – US, Oregon, Multnomah County, Washington County, 2001 and 2010
United States
Jobs (count)
Multnomah County
Oregon State
Washington County
2001
1,278,831
11,485
3,251
3,304
2010
1,446,380
9,658
2,446
2,655
Change (%)
13.1
-‐15.9
-‐24.8
-‐19.6
Wages (USD)
2001
92,050
78,876
80,642
85,749
2010
92,763
80,125
84,151
84,425
0.8
1.6
4.4
-‐1.5
Change (%)
Source: Bureau of Labor Statistics Quarterly Census and Employment Wages. Notes: Computer systems industry includes all subcodes under NAICS 5415. Only private sector data is represented. A Consumer Price Index (CPI) of 1.23 was used to adjust 2001 dollars to 2010 levels due to inflation.
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Table 5: Location Quotients (LQ) for Computer Systems – US, Oregon, Multnomah County, Washington County, 2001 and 2010 2001 Total jobs (count)
United States
Oregon State
Multnomah County
Washington County
109,304,802
1,343,240
380,379
211,936
1,278,831
11,485
3,251
3,304
1.2
0.9
0.9
1.6
LQ relative to state
N/A
N/A
1.0
1.8
LQ relative to US
N/A
0.7
0.7
1.3
106,201,232
1,318,288
350,418
212,152
1,446,380
9,658
2,446
2,655
Computer jobs (count) Computer job share (%)
2010 Total jobs (count) Computer jobs (count) Computer job share (%)
1.4
0.7
0.7
1.3
LQ relative to state
N/A
N/A
1.0
1.7
LQ relative to US
N/A
0.5
0.5
0.9
Source: Bureau of Labor Statistics Quarterly Census and Employment Wages. Notes: Computer systems industry includes all subcodes under NAICS 5415. Only private sector data is represented.
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Figure 1: Percent Population by Age – Oregon State, Multnomah County, and Washington County, 2008
Figure 2: Differences in Percent Male and Female by Age – Oregon, Multnomah County, Washington County, 2008
Source (both figures): PSU Population Research Center certified estimates (March 2009).
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Figure 3: Population Projections for the Year 2020 Using Three Methods & Two Baselines
Oregon State
Multnomah County
Washington County
Source: PSU Population Research Center certified estimates (March 2009). Note: “Linear, adjusted” values are extrapolated using the equation of the trend line, and then “adjusted” by adding/subtracting the difference between the model’s projected 2010 population and the actual population.
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