Airports’ contribution to regional economic growth can only be estimated relative to measurable changes in the regional economy. How has the population changed over time? How has the structure of the regional economy changed? On a year-to-year basis, the scale and extent of socioeconomic changes can be difficult to discern. But over time, trends emerge that reveal significant structural changes in the economy and factors that drive the demand for air transportation.

This section reveals key elements of how the country, states, and regions have changed in measures that are relevant to air service.

Population and Metropolitan Statistical Areas

Between 2000 and 2019, the total U.S. population slowly rose from 282 million to 328 million, an increase of 46 million (16 percent). That growth reflects a compound annual rate of growth of less than 1 percent. Over the same period, the extent of urbanization—the percentage of the total population that lives in urban areas—rose slightly, from 79 to 82 percent. According to the Census Bureau, only four states—Maine, Mississippi, Vermont, and West Virginia—have more people who live in rural areas than urban areas.

Urban areas are territories with a population of at least 2,500 people, at least 1,500 of which reside outside institutional group quarters (e.g., hospitals or prisons). The Census Bureau identifies two types of urban areas:

• Urbanized areas (UAs) of 50,000 or more people
• Urban clusters (UCs) of at least 2,500 and less than 50,000 people

“Rural” encompasses all population, housing, and territory not included within an urban area.

Most U.S. airports are located in or adjacent to areas defined as metropolitan statistical areas (MSAs). The general concept of an MSA is that of a core area containing a substantial population nucleus, together with adjacent communities having a high degree of economic and social integration with that core. Each MSA must have at least one UA of 50,000 or more inhabitants. “Micropolitan statistical areas” have smaller populations; they have a total population of less than 50,000 but must have at least one UC of at least 10,000. As of March 2020, there were 384 MSAs and 543 micropolitan statistical areas in the United States.

Because the boundaries of MSAs follow county borders, some MSAs cover huge geographies, even if the populations are relatively modest. For example, the Flagstaff (Arizona) MSA had a 2019 population of 143,000 but covered 18,661 square miles, which is more land area than Maryland (12,407 square miles, population 6.2 million), Massachusetts (10,565 square miles, population 7.0 million), or New Jersey (8,723 square miles, population 9.3 million).

Adjacent MSAs and micropolitan statistical areas are often integrated as a “combined statistical area” (CSA) if the larger region reflects broader social and economic interactions, such as wholesaling, commodity distribution, and weekend recreation activities. “U.S. Combined Statistical Areas” shows the CSAs (and component MSAs and micropolitan statistical areas) in the United States as of 2020.

U.S. Combined Statistical Areas

Employment by Industry

Breakdowns by industry for economic data are a vital component of data granularity because they make it possible to isolate the relative size and activity of specific industries in the economy (e.g., air transportation), which, in turn, makes it possible to conduct economic impact analysis.

For economic data in the United States, the most common industrial categorization system is the North American Industry Classification System (NAICS). NAICS was adopted in 1997, as a means to establish a high level of comparability in business statistics among the United States, Canada, and Mexico.[2] NAICS uses a six-tier industry grouping structure that becomes progressively more granular in definition at each level. For instance, two-digit NAICS codes identify each broad “sector” in the economy (e.g., Code 48 = Transportation), while six-digit NAICS codes signify each specific “national industry” (e.g., Code 481111 = Scheduled Passenger Air Transportation) that collectively makes up the given sectors.[3]

While the NAICS structure includes six different coding levels, most economic data from the key statistics agencies in the United States show industry breakdowns for the broadest tiers only, specifically, by “sector” (two-digit NAICS codes) and a select few “subsectors” (three-digit NAICS codes). The table below summarizes the key potential categories for each of these breakdown types. It also notes that the data are available on monthly, quarterly, and annual bases and for different levels of geography.

Availability of NAICS Data

The economy underwent notable structural change during the 20-year period from 2000 to 2019. Many of those changes reflected long-term trends:

• Employment in manufacturing (durable and non-durable goods) dropped by 4.5 million (26 percent). In 2000, manufacturing employment represented almost 13 percent of the total U.S. employment. By 2019, that share had dropped to 8 percent.
• Employment in information (which includes publishing, motion picture and sound recording, broadcasting and telecommunications, and information and data processing services) also dropped by 760,000 (21 percent). The sector’s share of national employment fell from 3 percent to 2 percent.

Employment in several sectors recorded significant growth between 2000 and 2019:

• Health care and social assistance rose by 7.5 million jobs (57 percent). As a percent of total U.S. employment, the health care sector’s share rose from 9 percent to 13 percent.
• Educational services (1.3 million jobs, 52 percent).
• Accommodations and food services (4.1 million jobs, 41 percent).
• Professional, scientific, and technical services (2.7 million jobs, 39 percent).
• Management of companies and enterprises (700,000 jobs, 39 percent).
• Transportation and warehousing (1.3 million jobs, 29 percent). Within that sector, employment more specifically related to warehousing—likely associated with the broad movement associated with e-commerce—increased by 730,000 jobs, or 142 percent.

Percentage Changes in Employment by Industry Sector and Total, 2019 vs. 2000

Change in Absolute Number of Employed by Industry Sector, 2019 vs. 2000

Regional Economic Growth and Strength

From 2000 through 2019, total employment in the U.S. economy grew by nearly 38 million jobs or 23 percent. As is well known, however, different regions of the country grew faster than others. States in the South and West generally grew more rapidly while those in the Great Plains and Great Lakes regions (the traditional “Rust Belt”) did not. The populations of Nevada, Utah, and Arizona all grew by more than 40 percent over the period. Conversely, The population of 10 states grew by less than 5 percent. West Virginia lost population. Employment growth in five states exceeded 40 percent: Utah (54%), Nevada (52%), Texas (48%), Florida (45%), and Arizona (42%).

Within the states, different regions also exhibited great variation in employment growth. Among all MSAs and CSAs, between 2008 and 2019, the average (median) increase in employment was 9 percent. Kansas City, Kansas; Knoxville, Tennessee; Cincinnati, Ohio; and Cedar Rapids, Iowa are examples of regions that grew at that rate. However, some regions’ economies have soared over the period and others have faired less well.

Urban Areas with the Greatest and Least Percentage Change in Employment Growth, 2008–2019

Different regions possess different economic attributes or strengths. These differences may arise from a region’s location or geography (e.g., port cities with concentrations in maritime manufacturing, locations near mineral deposits). Other differences may arise due to differentials in the key factors of production, including land, labor, and capital. A competitive advantage in any of these factors can trigger an economy of scale capable of generating higher wages and productivity levels. A good example is the specialized concentration of workers and firms in Silicon Valley. There are different ways to assess those strengths. Two stand out: Economic Clusters and Location Quotients.

It is not always possible to analyze changes over time in particular industry sectors. To protect the confidentiality of sensitive information, federal statistical agencies sometimes need to suppress the public release of employment and wage data. As a result, it is not always possible to see changes over time.

For example, in the tables showing percentage increases in regional professional, scientific, and technical (PST) employment, information was not available for all regions in 2008. As a result, changes from 2008 to 2019 could not be calculated. However, information might have been available for 2015, so users could see changes over subsequent periods. As a specific example, no information was available for PST employment in the Nashville area for 2008. Those data were available for other years, so it is clear that PST employment there grew by over 20,000 (23 percent) between 2015 and 2019.

Regions with Greatest Percentage Changes in Professional, Scientific, and Technical Employment, 2008–2019 and 2015–2019

Regional Employment Changes Associated with Air Cargo

Air cargo service is used by industries that require high-speed performance of air transportation. These include businesses that produce or consume perishable items; businesses that produce high-value goods for which the cost of shipment is a small part of the total cost of the product; and businesses that rely on aviation to meet urgent demands, changing schedules, or stringent delivery requirements. However, the movement of air cargo (both inbound and outbound) often includes relatively long ground transport segments. Shippers have shown that they are extremely price sensitive and are thus willing to move cargo and freight long distances by truck to reach airports where prices for air freight are most advantageous. Airports serving smaller cities tend to lose air cargo traffic to airports serving larger cities within 100 miles. As a result, it is difficult to relate air cargo and freight volumes at an airport to business activity in the immediate region.

Any parties involved are required to ensure air cargo is shipped on time and safely from one place to another, either domestically or internationally. These include air cargo terminal operators, freight forwarders, integrators, consolidators, ground handlers, and truckers. Perishable goods also require special storage. For airports with international operations, the value chain includes Customs inspection service.