>> NOTES ON SAMPLING VARIABLES

>> NOTES ON SAMPLING VARIABLES


PSU (Primary Selection Unit)

An abbreviated version of the Census MSA of which it is part for SR MSAs 
and Non-SR MSAs.  For non-MSAs the PSU Name is the name of the county
involved.  If there is more than one county in the non MSA (non MSA counties
were linked to reach a minimum measure of size of 5000 Households) it is named
for the county with the most Households in 1990.

The hundreds place of the Primary Selection Unit (PSU) for Cross Section
Segments that are all from the 1990 National Sample indicates when the segment
is in a Self Representing (SR) Metropolitan Statistical Area (MSA), a Non Self
Representing (Non SR) MSA or a Non MSA as designated by the U.S. Office of
Management and Budget.

100's are SR MSA areas
200's are Non SR MSA areas* 
300's are Non MSA areas**
400's are Non MSA PSU's from the 1980 National Sample Design

* PSU 434 is a Non Self Representing MSA from the 1980 National Sample Design.
**For NES 2000 all Non MSA PSU's are Non MSA's from the 1980 National Sample
Design. 

The tens place of the PSU for the 1990 National Sample indicate which Census
Division the segment is located in.  The variable Census Region (described on
page two) indicates the Census Region for each of the divisions mentioned
below.
 
       Division                  Region (Census Region)
       ------------------        ---------------------
10     New England               North East (1)
20     Middle Atlantic           North East (1)
30     East North Central        MidWest (2)
40     West North Central        MidWest (2)
50     South Atlantic            South (3)
60     East South Central        South (3)
70     West South Central        South (3)
80     Mountain                  West (4)
90     Pacific                   West (4)

The ones place of the PSU are simply sequential numbers within the division.


SEGMENT NAME

The name of the city or Census Place or Census MCD with the most housing 
units (HUs) within the area segment boundary.


BELT CODE

Code 1 includes all except two of the 28 1990 National Sample
Frame self-representing areas.  Central Cities of Denver,
Co MSA and Kansas City MSA are NOT to be coded 1.  Central
Cities of all other self-representing areas of the 1990
National Sample Frame are coded 1 (including Nassau-
Suffolk NY and Newark NJ as part of the NYC, NY-Northern
NJ CMSA; Los Angeles, Anaheim, and Riverside CA as part of
the LA-etc. CMSA; and San Francisco and Oakland CA as part
of the SF-Oakland CA CMSA).   For the most part, no 1990
Frame non-self-representing MSA Central Cities  are coded
1, except as noted below.  [NOTE: In 1990, the PSU
definition in New England states is the New England County
Metropolitan Area (NECMA).  This means that for the 1990
Frame segments in New England--there may be Central Cities
of MSAs included in the NECMA definition that are not in
the CMSA/MSA definition.  For example, in Boston MA (1990
frame) the Central Cities include not only those for
Boston MSA but some from other New England MSAs -- some of
which could be outside of the Boston CMSA definition and
could be coded `2'.  It also means that in the Manchester-
Nashua NH  NECMA (non-self-representing) there are two
segment selections in Nashua, NH (central city of Nashua
MA PMSA) which is part of the Boston MA CMSA and has
therefore been coded `1'.]

Central Cities - as designated in Metropolitan Statistical
Areas, 1990, U.S. Office of Management and Budget,
Washington, D.C. (June 1990).
Six largest CMSAs - Statistical Abstract of the United
States 1991, (111th Edition), U.S. Department of Commerce,
Economics and Statistics Administration, Bureau of the
Census, Table No. 38.  "70 Largest Metropolitan Areas--
Racial and Hispanic Origin Populations: 1990" Pp 33.
Suburbs - defined as all "urbanized areas" in the Primary
Area exclusive of the areas coded `1' and `2' above, plus
the remainder of any county which includes a central city
or parts of a central city. 


NECMA/SMSA

The NECMA is the New England County Metropolitan Area code
as described in the 1990 SRC National Sample Design and
Development documentation.
In 1990 the U.S. Census adopted slightly different wording
and abbreviations for metropolitan areas, now known
collectively as Metropolitan Areas (MAs).  What in 1980
were Standard Metropolitan Statistical Areas (SMSAs)
became in 1990 either Metropolitan Statistical Areas
(MSAs) or Primary Metropolitan Statistical Areas
(PMSAs).   MSA is used for a metropolitan area which
stands alone, i.e., is not a part of a Consolidated
Metropolitan Statistical Area (CMSA).  PMSA is used for a
metropolitan area which is part of a larger CMSA.

The metropolitan area standards for the 1990's generally
reflect a continuity with those adopted for the 1980's and
maintain the basic concepts originally developed in 1950.
The few substantive changes made between 1980 and 1990 are
detailed in the Federal Register, Vol. 55, No.62 cited in
the footnote.

New England County Metropolitan Areas (NECMAs) provide an
alternative to the official city-and-town based
metropolitan statistical areas in that Census region for
the convenience of data users who desire a county-defined
set of areas.  NECMAs have their separate definition
standards detailed in the Federal Register (p. 12159).
Since the 1990 SRC National Sample primary stage of
selection was based on the NECMA in New England, the 1990
NECMA  is provided in place of 1990 MSA or PMSA for this
variable.


CMSA

The 1990 Consolidated Metropolitan Statistical Area (CMSA)
codes are in most cases identical to the 1980 SCSA codes
with the exceptions noted in parenthesis.
In addition to the major changes noted, minor changes in
SCSA and CMSA names have also occurred between 1980 and
1990.