The Science and Engineering Indicators (SEI) State Indicators data tool contains trend data for most indicators. These data are available to download within the data tool and from the State Indicators Export Data page.

Standard Errors

Standard errors of indicators are provided, depending on the type of data used for the indicator ratio. When standard errors are applicable, they are available by selecting the “Download Indicator standard error” at the downloads button under Export. The availability of standard errors is categorized as follows:

• Censuses. These are complete population counts; therefore, no standard error is associated with the estimate.
• Samples. Standard errors for estimates, where available, are provided by the source. Data from sources such as the National Assessment of Educational Progress, American Community Survey, and Survey of Doctorate Recipients are based on samples of target populations. Estimated standard errors are provided where available but may be incomplete for some data sets; for example, standard errors are not available prior to 2007 for the Occupational Employment Statistics survey. The business research and development (R&D) data set has associated standard errors for its values, but some historical values of standard errors are not available due to updates to the estimates but not to the standard errors.
• Statistical Models. Standard errors cannot be provided for some estimates due to the estimating techniques of the data source (e.g., gross domestic product [GDP] data and Census-based population estimates).
• Source data set. For data series where the standard error information for the source data is available, approximation formulas for combining sampling errors were used. Because the source data used to derive these estimates are from different independent samples, no covariance term is included in the formulas.

Standard error tables are provided for download except for where the standard errors are not applicable or not available.

The following formulas were used to estimate standard errors for derived data series.

Sums and Differences

Where available for aggregate estimates, such as the total for the United States, sampling errors were collected for the aggregate estimate as provided by the source.

In a few cases, aggregate estimates were calculated from individual parts of the aggregate, and therefore, sampling errors also had to be calculated based on the individual parts of the aggregate. The same formula was also used for computing the standard error for the difference of two estimates. It was assumed that the covariance between the individual parts was negligible.

This formula was used, where applicable, for roll-ups such as national values.

Quotient

This formula was used to calculate the standard errors of the ratios (assuming X and Y are uncorrelated, using the first order Taylor series expansion, which is an approximate but widely used and accepted approach).

Relative Standard Error

Errors for some estimates are available only as the relative standard error or percent relative standard error.

Therefore, to transform the percent relative standard error to standard error, the following equation was used:

Proportion

This formula was used to calculate the standard errors of proportion-based indicators (where X is a subset of Y):

Constant Dollar Data

State Indicators presents data as current dollars. To facilitate comparisons over time, many indicators can also be presented as inflation-adjusted values by clicking the checkbox for “Adjust values for inflation.” The data tool uses the implicit price deflator for GDP for the United States, which is regularly reported by the Bureau of Economic Analysis (BEA) in the Department of Commerce (https://www.bea.gov/national/index.htm#gdp). Use of the implicit GDP price deflator as the basis for R&D inflation adjustments is the standard practice of the national statistical offices for all the world’s major economies. At present, the base year for inflation adjusted, constant dollars is 2017; for a further explanation, see https://bea.gov/help/faq/513 and https://en.wikipedia.org/wiki/GDP_deflator.

The constant dollar adjustment is available in State Indicators for all financial indicators, except for ratio or percentage indicators where both the numerator and denominator are expressed in dollar units. This option is available in the table and chart views of the data tool.

Table S-A provides the GDP price deflators used in State Indicators. These price indices are for the national GDP and are not adjusted for states or counties. The State Indicators tables that are available for download present information as current dollars only. The data in Table S-A can be used to replicate the constant dollar information in State Indicators. It may also be applied to the standard error tables, as applicable.

Statistical Testing

As noted in the overview, indicators based on estimates have associated standard errors, and therefore, small differences in numbers may not be statistically significant.

Knowledge- and Technology-Intensive Industry Employment

This tool and the Production and Trade of Knowledge- and Technology-Intensive Industries report defines knowledge- and technology-intensive (KTI) industry employment as those occupations with the highest R&D intensities based on a taxonomy of economic activities developed by the Organisation for Economic Co-operation and Development (OECD). They consist of nine manufacturing industries—chemicals and chemical products; pharmaceuticals; computer, electronic, and optical products; electrical equipment; other machinery and equipment; motor vehicles, trailers, and semi-trailers; air and spacecraft and related machinery; railroad, military vehicles and other transport equipment; medical and dental instruments—and three services industries—information technology (IT) and other information services; software publishing; and scientific research and development.

Each industry is defined by a four-digit code that is based on the North American Industry Classification System (NAICS). The KTI data reflect the 2012 NAICS codes. For more detailed information on the KTI industries and methodological approach, see Indicators 2022 report, “[2022] Production and Trade of Knowledge- and Technology-Intensive Industries Technical Appendix.”

As part of the calculation of KTI employment in the Indicators 2022 report (Indicators 2022 “[2022] Production and Trade of Knowledge-and Technology-Intensive Industries), employment information from the 2017 Economic Census was used to prorate estimated employment based on the Public Use Microdata Sample for modified NAICS industries partially assigned to multiple International Standard Industrial Classification (ISIC Revision 4) industries. This creates internationally comparable data. Caution should be exercised when making international comparisons because international data is compiled from multiple national sources and are prone to varying issues of quality and reliability. The partial employment rates for modified NAICS industries 3335 and 332MZ are shown in Table SAKTI-3 of the KTI Technical Appendix based on the 2017 Economic Census. These partial employment rates were used for the estimation of KTI employment for data years after 2017. Table S-B shows the partial employment rates of modified NAICS industries 3335 and 332MZ based on the 2012 Economic Census (for data years 2013 through 2017) and the 2017 Economic Census (for data years after 2017).

Population Adjustments for County Geographic Boundary Changes

Since 2000, the geographic boundaries of several counties and county equivalents have changed. The State Indicators data tool displays present-day county boundaries as used by BEA. BEA made the following modifications to the population data:

• Kalawao County, Hawaii is combined with Maui (Kalawao does not have its own local government; it is administered by the State of Hawaii).
• The independent cities of Virginia with populations of less than 100,000 have been combined with an adjacent county. In the name of the combined area, the county name appears first and is followed by the city name or names.

Additionally, to account for geographic boundary changes, the population data used in county-level indicators are adjusted based on the type of boundary change. The methodology for these adjustments is described in more detail below.

• County split: County populations are estimated before the split based on the population proportions of each of the counties after the split. For example, County Z splits into Counties A and B in 2010. County A is 40% of the combined population and County B is 60% of the combined population in 2010. The estimate of County A’s population in 2009 is 40% of County Z’s 2000 population and the estimate of County B’s population in 2009 is 60% of County Z’s 2000 population. The same method is used for all years displayed before the split. Counties affected by splits include:
  • Skagway-Hoonah-Angoon Census Area: AK split into Skagway Municipality and the Hoonah-Angoon Census Area in 2007
  • Wrangell-Petersburg Census Area: AK split into Wrangell City and Borough and Petersburg Census Area (now Petersburg Borough) in 2008
  • Valdez-Cordova Census Area: AK split into Chugach Census Area and Copper River Census Area in 2019
• County name change: County populations before the name change are linked to the county populations after the name change. The following changes are classified as county name changes.
  • Prince of Wales-Outer Ketchikan Census Area was renamed Prince of Wales-Hyder Census Area in 2008
• County secession: In 2001, Broomfield County, CO was formed from portions of four other counties: Adams, Boulder, Jefferson, and Weld. Broomfield County’s 2000 and 2001 population is calculated as the sum of the portions of Broomfield City’s population in each of the four parent counties using data from the Census Bureau’s Population Estimates Program.

Table S-A

Calendar-year price deflators: 1990–2024

GDP = gross domestic product.

NOTE: The base year (= 1.0000) used for the constant dollar calculations is 2017, consistent with the current Bureau of Economic Analysis and Office of Management and Budget convention.

SOURCE: Bureau of Economic Analysis, National Economic Accounts, Gross Domestic Product, accessed 5 May 2025.

Science and Engineering Indicators

Table S-B

Partial employment rates of modified NAICS industries 3335 and 332MZ (Rate)

NAICS = North American Industry Classification System.

SOURCES: Census Bureau, 2012 Economic Census, accessed 8 May 2022. Census Bureau, 2017 Economic Census, accessed 2 May 2022.

Science and Engineering Indicators