Current Population Survey Design and Methodology - Census Bureau

demographic components often cited in the literature consist
of births, deaths, and net migration. This appendix
also refers to changes in the institutional and active-duty
Armed Forces populations, which affect the CPS control
universe.
The CPS control universe is characterized by two
attributes: (1) restriction to the civilian noninstitutionalized
population, and (2) modification of census data by
race. Each of these defining concepts appears separately
in this glossary.
Emigration is the departure of a person from a country of
residence, in this case the United States. In the present
context, it refers to people legally resident in the United
States but is not confined to legally permanent residents
(immigrants) who make their usual place of residence outside
of the United States.
Population estimates are population figures that do not
arise directly from a census or count but can be determined
from available data (e.g., administrative data).
Population estimates discussed in this appendix stipulate
an enumerated base population, coupled with estimates of
population change from the enumeration date of the base
population to the date of the estimate.
The institutional population refers to a population universe
consisting of inmates or residents of CPS-defined
institutions, such as prisons, nursing homes, juvenile
detention facilities, or residential mental hospitals.
Internal consistency of a population time series occurs
when the difference between any two population estimates
in the series can be construed as population change
between the reference dates of the two population estimates.
International migration is generally the change of a person’s
residence from one country to another. In the
present context, this concept includes change of residence
into the United States by non-U.S. citizens and by previous
residents of Puerto Rico or the U.S. outlying areas, as well
as the change of residence out of the United States by
people intending to live or make their usual residence
abroad, in Puerto Rico, or the outlying areas.
Legal permanent residents are people whose right to
reside in the United States is legally defined either by
immigration or by U.S. citizenship. In the present context,
the term generally refers to noncitizen immigrants.
Modified race describes the census population after the
definition of race has been aligned with definitions from
other administrative sources.
The natural increase of a population over a time interval
is the number of births minus the number of deaths during
the interval.
Population projections are population figures relying on
modeled or assumed values for some or all of their components,
and therefore not entirely calculated from actual
data. Projections discussed in this appendix stipulate a
base population that may be an estimate or count, and
components of population change from the reference date
of the base population to the reference date of the projection.
The reference date of an estimate or projection is the date
to which the population figure applies. The CPS control
reference date, in particular, is the first day of the month
in which the CPS data are collected.
The resident population of the United States is the population
usually resident in the 50 states and District of
Columbia. For the census date, this population matches
the total population in census decennial publications,
although applications to the CPS series beginning in 2001
include some count resolution corrections to Census 2000
not included in original census publications.
A population universe is the population represented in a
data collection, in this case, the CPS. It is determined by a
set of rules or criteria defining inclusion and exclusion of
people from a population, as well as rules of classification
for specified geographic or demographic characteristics
within the population. Examples include the resident
population universe and the civilian population universe,
both of which are defined elsewhere in this glossary. Frequent
reference is made to the ‘‘CPS control universe,’’
defined separately in this glossary as the civilian noninstitutional
population residing in the United States.
CPS Population Controls: Estimates or Projections?
Throughout this appendix, the independent population
controls for the CPS will be cited as population projections.
Throughout much of the scientific literature on
population, demographers take care to distinguish the
concepts of ‘‘estimate’’ and ‘‘projection’’; yet the CPS population
controls lie close to the line of distinction. Generally,
population estimates relate to past dates, and in order to
be called ‘‘estimates,’’ must be supported by a reasonably
complete data series. If the estimating procedure involves
the computation of population change from a base date to
a reference date, the inputs to the computation must have
a solid basis in data. Projections, on the other hand, allow
the replacement of unavailable data with assumptions.
The reference date for CPS population controls is in the
past, relative to their date of production. However, the
past is so recent—3 to 4 weeks prior to production—that
for all intents and purposes, CPS could be projections. No
data relating to population change are available for the
month prior to the reference date; very little data are available
for 3 to 4 months prior to the reference date; no data
for state-level geography are available past July 1 of the
C–2 Derivation of Independent Population Controls Current Population Survey TP66
U.S. Bureau of Labor Statistics and U.S. Census Bureau