Shifting Demographics: Out with the New, In with the Old

Katelyn Chamarro, Research Economist

The nation’s demographic mix is changing but what does that mean for Tucson? In recent years, demographics have shifted with the population aging and birth rates declining. In order to plan for the future, it’s important to understand how demographic changes impact our region. This article explores demographic elements such as dependency ratios, population splits, and birth rate breakdowns by geography and ethnicity. Another great resource on demographics in Southern Arizona is the Population Profile indicator on the MAP, which covers population by age and race and ethnicity.

A dependency ratio illustrates the proportion of a population that is younger and/or older than the working age population in an area. A higher dependency ratio indicates that a large proportion of the population is either young, old, or a mix of the two. Regions that have a high dependency ratio tend to rely more heavily on public services. As the population ages and birth rates slow, old age dependency ratios may continue to increase. According to the U.S. Census Bureau, it is estimated that “by 2060, there will be just two-and-a-half working-age adults for every retirement-age person.” Likewise, they estimate there will be more people age 65 and older than those under the age of 18 by 2034.1

When comparing the state of Arizona to other western states, Arizona ranked third highest out of 10, at 67.8, for total age dependency (see Figure 1). The total dependency ratio includes those younger than 18 and 65 or older. The overall ratio for the Tucson Metropolitan Area (MSA) was 67.9, on par with the state, but significantly higher than the nation (61.9). Tucson also had the highest total dependency ratio among peer western MSAs. In terms of Arizona counties, there was much variation, with La Paz County posting the highest total dependency ratio at 128.6 and Coconino County posting the lowest at 49.2. Pima County (also the Tucson MSA) posted one of the lowest ratios out of Arizona counties.

Figure 1: Total Dependency Ratio (2017)

Of 10 peer western states, Arizona fell in the middle of the pack for child dependency ratio at 39.1, which tied New Mexico for fourth. The child dependency ratio depicts the proportion of the population that is younger than 18 years of age. As Figure 2 illustrates, the Tucson MSA posted a lower child dependency ratio than the state at 35.6 in 2017. This was also lower than the U.S. child dependency ratio (36.6). Compared to 12 peer MSAs, Tucson ranked eighth for child dependency ratio. Child dependency ratios in Arizona counties varied from 31.2 in Coconino to 49.3 in Santa Cruz.

Figure 2: Child Dependency Ratio (2017)

Arizona ranked first for old age dependency among peer western states with a ratio of 28.7, more than three percentage points above the U.S. Tucson had a high old age dependency ratio at 32.3, much higher than both the state and nation. Compared to peer MSAs, Tucson ranked the highest and was followed by Albuquerque at 26.3. La Paz had the highest old age dependency ratio among Arizona counties at 89.9. Most counties in Arizona had old age dependency ratios above the state and U.S., although the ratios varied widely, with Coconino County posting the lowest at 18.0. The old age dependency ratio, as depicted in Figure 3, shows the proportion of the population that is 65 and older.

Figure 3: Old Age Dependency Ratio (2017)

Population pyramids illustrate the gender and age distribution of an area. Each pyramid shows the percentage of the population that falls into the specific age group and gender category. In 2017, Tucson’s population breakdown was less equally distributed than the nation’s breakdown (see Figure 4a and 4b). For instance, Tucson had a much larger number of those age 20 to 24, both male and female, than the U.S. In Tucson, 4.5% of the population was 20 to 24 years old and male, and 4.3% of the population was 20 to 24 years old and female. The spike in population for those aged 20 to 24 is likely due to the large presence of college students brought in by the University of Arizona. Comparatively, U.S. figures in the 20 to 24 age group were 3.5% male and 3.3% female. Additionally, Tucson had a larger percentage of the population in the 65 years and older age groups for both male and female than the U.S. This is due to the large number of retirees who reside in the region.

Figure 4a-b: Population Pyramids

The birth rate has declined in Arizona from 16.4 births per 1,000 people in 2000 to 11.7 births per 1,000 in 2017, a decrease of 28.7% (see Figure 5). The birth rate for the Tucson MSA has consistently been lower than the state, but has followed a similar trend overall, falling from 14.7 in 2000 to 10.7 in 2017. Holding migration rates constant, slowing birth rates likely aid in driving Arizona and Tucson’s old age dependency ratios up. To learn more about declining birth rates, check out Arizona's Baby Bust, an article by EBRC director George Hammond which explores birth rates and their impact. 

Figure 5: Birth Rates Trend

In 2017, there were 14.3 Hispanic births per 1,000 Hispanic people in Tucson and 8.2 white, non-Hispanic births per 1,000 white, non-Hispanic people. As seen in Figure 6, Hispanic birth rates were higher than white, non-Hispanic rates across the board. The Phoenix MSA posted the highest birth rates of the geographies for both ethnicities, while the Tucson MSA posted the lowest.

Figure 6: Birth Rates by Ethnicity (2017)

How is it measured?

Birth rates are calculated by dividing number of births by the population and multiplying by 1,000 to get births per 1,000 people. Data for Arizona is from the Arizona Department of Health Services, while the U.S. and state figures are from the National Vital Statistics Report and the U.S. Census Bureau Population Estimates program. Child dependency ratio is calculated by dividing the under 18 population by the 18-64 year old population and multiplying by 100. Old age dependency is calculated by dividing the 65 plus population by the 18-64 population and multiplying by 100. The total age dependency ratio is calculated by combining under 18 and 65 plus, dividing by the 18-64 population, and multiplying by 100. These age dependency ratios are calculated using data from the U.S. Census Bureau Population Estimates program.


  1. Older People Projected to Outnumber Children for the First Time in U.S. History. (September, 2018), United States Census Bureau,