INFO file:  FIPS_ALT.DAT

NOTE:     Explanation about the number of Counties in the SAA and
          the use of FIPS codes.

     There are 151 Counties in the SAA.  Sometimes, references
are made about 135 Counties in the SAA.  The 135 County
references ignore the 'City' County units in Virginia.  There are
16 such 'City' Counties in Virginia, within the SAA.  Those
'City' County units are functional equivalents of other County
political units in the rest of the United States.

     Data analysis for the SAA was awkward at times due to the
conflicting number of Counties.  The data provided with only the
135 number of Counties, used the FIPS code of the larger 'normal'
County to which a 'City' County was closest associated with.  In
this sense the 'City' unit was ignored and its area was absorbed
into the most likely County.  Often, the 'City' units are
completely surrounded by one County.

     To further complicate the issue, the Bureau of Economic
Analysis (BEA), provided a set of unique FIPS codes for County
units that were joined.  Only Roanoke, VA remained an intact
'City' County unit for the BEA FIPS codes.  The only place were
the BEA FIPS are used is with the County Census Projections. 
(/saa1/saa_tab  INFO file: censproj.dat)

     Three versions of the Counties coverage are provided for
correctly relating data.  These are:

     counties  - 151 County units
     co_135    - 135 County units
     co_136    - 136 County units

     An INFO file with all of the various versions of the FIPS
codes related to the true County Units are contained in
/saa1/saa_tab.  The INFO file is FIPS_ALT.DAT.

     FIPS_ALT.DAT
     151 records

     FIPS      - True FIPS code for the County Units
     FIPS_135  - Common use, where 'City' units are eliminated
     FIPS_136  - Same as FIPS_136 except that Roanoke, VA retains 
                 its true FIPS and boundaries.
     BEA_FIPS  - Unique FIPS assigned to County units that are    
                 combined for census projections by BEA.

     Note that the datasets (INFO files) in saa_tab that employ
the 135 number of counties version are related by FIPS, not
FIPS_135.  One simply needs to observe whether or not the dataset
has 135 records or 151 records in order to chose the appropriate
counties coverage.  Some datasets have seven additional records
to provide state totals.  In those cases you see either 142 or
158 records.

Karl A. Hermann
3/18/96