Fact Sheet
Differences between the Income
and Poverty Estimates from the American Community Survey and the Annual
Social and Economic Supplement to the Current Population Survey
August 19,
2004
When fully implemented, the American Community
Survey (ACS) will be the largest household survey in the United States. Like
the decennial census long form it is designed to replace, the ACS provides
labor force estimates for small geographic areas – most cities, counties, and
metropolitan areas of 250,000 or more during the testing phase, and, beginning
in 2010, the ACS will use multi-year averages to provide estimates for all
areas down to census tracts/block groups. Estimates for the nation and states
are also available. All ACS estimates are updated annually.
Because of its detailed questionnaire
and its experienced interviewing staff, the Current Population Survey (CPS)
Annual Social and Economic Supplement (ASEC) is a high quality source of
information used to produce the official annual estimate of poverty, and
estimates of a number of other socioeconomic and demographic characteristics,
including income, health insurance coverage, school enrollment, marital status,
and family structure.
The following chart summarizes the key
differences between the ACS and the CPS:
|
American Community Survey |
Current Population Survey |
Principal
Purpose |
Replace decennial census long form by
providing annual (or multi-year average) estimates of selected social,
economic, and housing characteristics of the population for many geographic
areas and subpopulations. |
Produce specific socioeconomic and
demographic estimates for the United States, and estimates for states for
selected characteristics and subpopulations. Provide timely estimates of
income, as well as official poverty estimates |
Geography |
Nation, states, and cities and
counties of 250,000 or more.
Eventually, areas as small as census tracts using multi-year averages. |
Nation, regions, and states for
selected characteristics. |
Sample
Size |
About 800,000 addresses per year
during the testing phase (2000-2004); about 3 million addresses per year when
fully implemented (planned for 2005). Data are collected from about
one-twelfth of the sample each month. |
Annual sample size is about 100,000
addresses. |
Data
Collection Method |
Mail, telephone, and personal-visit
interviews for the 50 states and the District of Columbia. About half the
responses are obtained by mail. When fully implemented, the ACS will include
Puerto Rico. The ACS is a mandatory survey. |
Telephone and personal-visit
interviews for the 50 states and the District of Columbia. The CPS is a
voluntary survey. |
Residency
Status |
The ACS includes a person at the
address where they are at the time of the survey if they have been there, or
will be there, more than 2 months, whether or not they have a “usual
residence elsewhere.” |
The CPS
sample unit’s householder (one of the people in whose name the unit is rented
or owned) must consider the unit to be their place of usual residence (where
they spend most of the time during the year) to be counted as an occupied
unit, which is traditional in most censuses and housing surveys. If a family
has more than one home, the interviewer has to determine if the sample unit
is their usual residence. |
Population
Universe |
The testing phase of the ACS includes
the household population. This
universe includes both the civilian and military population in households and
excludes the group quarters population.
When fully implemented, the ACS will include both the household and the group
quarters populations (that is, the resident
population). The group quarters population consists of the
institutionalized (such as people in correctional institutions or nursing
homes) and the noninstitutionalized (most of whom are in college dormitories).
The weighting is controlled to population estimates as of July 1 (e.g., July
1, 2003 for the 2003 ACS). |
The CPS includes the civilian noninstitutionalized population.
This universe includes civilians in households, people in noninstitutional group
quarters (other than military barracks) and military in households living off
post or with their families on post (as long as at least one household member
is a civilian adult). The universe
excludes other military in households and in group quarters (barracks), and
people living in institutions. The weighting is controlled to population
estimates as of March 1 (e.g., March 1, 2004 for the 2004 CPS ASEC). |
Time
Period Covered |
Monthly interviews conducted January
to December 2003 asked about income in the previous 12-month period, yielding
a total time span covered by responses of 23 months. The survey’s 12-month
estimates are centered on December 15, 2002. |
Monthly interviews conducted from
February to April 2004 ask about calendar year 2003 income. The survey’s
12-month estimates are centered on July 1, 2003. |
Length
and Detail of Questions |
Using a series of eight questions,
the ACS asks about money income, plus one type of noncash benefit (food
stamps) during the previous 12 months. |
CPS asks a series of questions about
more than 50 sources of income, including questions about the amount of
several noncash benefits such as food stamps and employment-related health
insurance, during the previous calendar year. |
Inflation
Adjustment |
All dollar values for income are
adjusted to latest calendar year of estimates using the Consumer Price Index
for the date collected versus the average for the year. |
None. |