The Business Dynamics Statistics-Coastal Counties (BDS-CC) experimental data product uses county-level establishment geography to merge the Longitudinal Business Database (LBD) with a list of coastal counties from the National Oceanic and Atmospheric Administration (NOAA).  NOAA classifies counties based on whether they belong to the Coastal Watershed or not, using “NOAA coastal watersheds and U.S. Geological Survey (USGS) coastal cataloging units as delineated in the NOAA Coastal Assessment Framework.”  The focus is on “land areas within which water flows into the ocean or Great Lakes” and expands beyond the counties that are directly adjacent to water.  Counties are considered Coastal Watershed if they meet at least one of the following criteria: “(1) at a minimum, 15 percent of the county’s total land area is located within a coastal watershed or (2) a portion of or an entire county accounts for at least 15 percent of a coastal USGS 8-digit cataloging unit.”  There are some counties on the Coastal Watershed list that are exceptions to these criteria and these are further described in the NOAA Coastal Counties document (NOAA, Defining Coastal Counties).

For the BDS-CC product, the broader category of Coastal Watershed counties is split into two groups – Coastal Shoreline (CS) and Coastal Non-Shoreline (CNS).  NOAA defines Coastal Shoreline counties as those counties which are directly adjacent to the ocean, major estuaries, and the Great Lakes and Coastal Non-Shoreline are those counties in the Coastal Watershed that don’t directly border the water.  To classify the remaining counties, Non-Coastal (NC) counties are defined as those that have a county designation in the LBD but are not on the NOAA coastal county list.  There are two additional categories of counties: Statewide (SW) and Unknown (U).  These categories are assigned to records when the specific location of the establishment is unknown or it can only be classified in a state and not at a more granular level of geography.  This is consistent with the core BDS and more information about these two categories can be found on the BDS Codebook and Glossary webpage.  This results in each county in the LBD being placed into one of five mutually exclusive categories: CS, CNS, NC, SW, or U.  This coastal designation is then used to stratify statistics in the BDS-CC tables.

All coastal designations are based on 2010 county boundaries.  Very few county boundary changes have occurred since 2010. One major exception is Connecticut, which changed from county designations to council of governments (COGs).  All eight Connecticut counties are listed in NOAA’s Coastal Watershed list.  Therefore, when we extrapolate to the COGs, all of the COGs are also included in the Coastal Watershed list.  To determine the COGs that are Coastal Shoreline, we select those that directly border the water.  For more information about county boundary changes, please see Appendix A in Chow and Stinson, 2025.

To provide additional geographic detail to our data tables, each coastal county is further classified into one of four coastal regions: Atlantic, Great Lakes, Gulf of Mexico, and Pacific.  For the most part, all coastal counties in a state are in the same coastal region.  The three exceptions are Florida (some counties in the Atlantic region and others in Gulf of Mexico), New York (with counties in the Atlantic and Great Lakes regions), and Pennsylvania (with counties in the Atlantic and Great Lakes regions).

To tabulate our data by different urban/rural categories, we put each of the counties into an urban/rural classification based on four categories: predominantly urban, mostly urban, mostly rural, and predominantly rural.  These categories are consistent with those used in other BDS products (for example, the BDS-Single Unit Firms with Revenue and BDS-SBA Covid Response tables).  The urban-rural categorization is based on the percentage of the total population count from the 2020 Decennial Census living in urban areas.  The definitions are as follows:

• Predominantly Urban (PU) - Urban population greater than or equal to 80%
• Mostly Urban (MU) - Urban population greater than or equal to 50% and less than 80%
• Mostly Rural (MR) - Urban population greater than or equal to 20% and less than 50%
• Predominantly Rural (PR) - Urban population less than 20%

The remaining variables in the BDS-CC are analogous to those used in the core BDS: industry sector, 3-digit NAICS industry, 4-digit NAICS industry, firm age coarse, firm size coarse, initial firm size coarse, establishment age coarse, establishment size coarse, and initial establishment size coarse.  Further details about these variables and their definitions can be found on the BDS Technical Documentation website.

Additionally, the BDS-CC follows the BDS Methodology to calculate the various employment and entity change statistics reported in the tables.

References

Chow, M., & Stinson, M. (2025). Business Dynamics Statistics of Coastal Counties: A Description of Differences in Coastal Areas Over Time. CES Discussion Paper Series, CES-WP-25-08, Center for Economic Studies, U.S. Census Bureau.

NOAA. “Defining Coastal Counties.” https://coast.noaa.gov/data/digitalcoast/pdf/defining-coastal-counties.pdf

Questions?  Contact us at ces.bds@census.gov.