In our review of ACS PUMS, we have found what we think is a workplace coding problem and concerned that the coding error will be carried forward into the CTPP.   The Census workplace coding problem was identified comparing change in employment estimates between 2000 and 2010 from BEA and BLS compared to Place of Work (POW) coding in Census long form/ACS over the same 10 year period.



2000-2010  BEA

2000-2010 BLS

2000 Census to 2010 ACS

Baltimore City




Baltimore County









It is important to understand that Baltimore City is an Independent City and is NOT included in Baltimore County.  Baltimore City is a county-equivalent.


We are wondering if other metropolitan areas are finding results using the ACS workplace coding that are divergent from other employment sources.

We are wondering if our problem is mostly due to the city and county having the same name, or if there is some other issue.




Detail results from the Baltimore MPO trend analysis follows.


The Baltimore MSA in 2010 contained 2.7 million persons within six political subdivisions (five counties [Anne Arundel, Baltimore, Carroll, Harford, and Howard] and one independent city [Baltimore City]).  All six political subdivisions have a 2010 population in excess of 100,000, allowing for designation of Public Use Microdata Areas (PUMAs) within each political subdivision for the Baltimore MSA.   Our concern in POW coding relates to Baltimore County and the independent City of Baltimore.  (Baltimore City is NOT an incorporated City within Baltimore County.  Residents of Baltimore City are NOT residents of Baltimore County.  The independent City of Baltimore’s political status is equivalent to a county.)


Bureau of Labor Statistics (BLS) nonfarm annual estimates for employment within Baltimore City was reported to have decreased 13.8% (408.4 to 352.0 thousand jobs) between 2000 and 2010.

Bureau of Economic Analysis (BEA) table CA25N was used to estimate employment within the Baltimore region’s six political subdivisions.  BEA reported a -13.4% reduction in Baltimore City employment between 2000 and 2010.  Job growth between 2000 and 2010 was estimated at 13.3% for Baltimore County.



An analysis of the 2000 decennial Census long form and 2010 ACS POW coding report  contradicting trends compared to those reported in the BEA and BLS estimates.  Census 2000 to 2010 POW trend seems reasonable compared to the BEA trend for Anne Arundel, Carroll, Harford and Howard Counties.  Baltimore County POW coding results in a 3.9% growth in Census reported primary job locations and Baltimore City Census POW coding results in a 2.2% growth in reported primary job locations.  Our concern is that during the review of addresses that do not geocode automatically Baltimore City is receiving Baltimore County reported primary POW locations.



We are hoping other urban area analysis of Census POW coding can help focus further analysis.  We feel there is an allocation/gecoding issue but are unsure if the error is related to Baltimore City’s status as an independent city or confusion in having a county and city with the same name.


Looking forward to hearing from others on analysis of POW coding.




Charles M. Baber

Principal Transportation Planner

Baltimore Metropolitan Council

Offices @ McHenry Row

1500 Whetstone Way, Suite 300

Baltimore MD 21230

410-732-0500 Ext. 1056


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