POVERTY STATUS IN 1999
The poverty data were derived from answers to long-form questionnaire Items 31 and 32, the
same questions used to derive income data. (For more information, see ‘‘Income in 1999.’’) The
Census Bureau uses the federal government’s official poverty definition. The Social Security
Administration (SSA) developed the original poverty definition in 1964, which federal interagency
committees subsequently revised in 1969 and 1980. The Office of Management and Budget’s
(OMB’s) Directive 14 prescribes this definition as the official poverty measure for federal agencies
to use in their statistical work.
Derivation of the Current Poverty Measure
When the Social Security Administration (SSA) created the poverty definition in 1964, it focused on
family food consumption. The U.S. Department of Agriculture (USDA) used its data about the
nutritional needs of children and adults to construct food plans for families. Within each food
plan, dollar amounts varied according to the total number of people in the family and the family’s
composition, such as the number of children within each family. The cheapest of these plans, the
Economy Food Plan, was designed to address the dietary needs of families on an austere budget.
Since the USDA’s 1955 Food Consumption Survey showed that families of three or more people
across all income levels spent roughly one-third of their income on food, the SSA multiplied the
cost of the Economy Food Plan by three to obtain dollar figures for the poverty thresholds. Since
the Economy Food Plan budgets varied by family size and composition, so too did the poverty
thresholds. For 2-person families, the thresholds were adjusted by slightly higher factors because
those households had higher fixed costs. Thresholds for unrelated individuals were calculated as
a fixed proportion of the corresponding thresholds for 2-person families.
The poverty thresholds are revised annually to allow for changes in the cost of living as reflected
in the Consumer Price Index (CPI-U). The poverty thresholds are the same for all parts of the
country — they are not adjusted for regional, state or local variations in the cost of living. For a
detailed discussion of the poverty definition, see U.S. Census Bureau, Current Population Reports,
‘‘Poverty in the United States: 1999,’’ P-60-210.
How Poverty Status is Determined
The poverty status of families and unrelated individuals in 1999 was determined using 48
thresholds (income cutoffs) arranged in a two dimensional matrix. The matrix consists of family
size (from 1 person to 9 or more people) cross-classified by presence and number of family
members under 18 years old (from no children present to 8 or more children present). Unrelated
individuals and 2-person families were further differentiated by the age of the reference person
(RP) (under 65 years old and 65 years old and over).
To determine a person’s poverty status, one compares the person’s total family income with the
poverty threshold appropriate for that person’s family size and composition (see table below). If
the total income of that person’s family is less than the threshold appropriate for that family, then
the person is considered poor, together with every member of his or her family. If a person is not
living with anyone related by birth, marriage, or adoption, then the person’s own income is
compared with his or her poverty threshold.
Individuals for whom poverty status is determined. Poverty status was determined for all
people except institutionalized people, people in military group quarters, people in college
dormitories, and unrelated individuals under 15 years old. These groups also were excluded from
the numerator and denominator when calculating poverty rates. They are considered neither
‘‘poor’’ nor ‘‘nonpoor.’’
Specified poverty levels. For various reasons, the official poverty definition does not satisfy all
the needs of data users. Therefore, some of the data reflect the number of people below different
percentages of the poverty level. These specified poverty levels are obtained by multiplying the
official thresholds by the appropriate factor. For example, the average income cutoff at 125
percent of the poverty level was $21,286 ($17,029 x 1.25) in 1999 for family of four people.
Poverty Threshold in 1999, by Size of Family and Number of Related Children Under
18 Years Old
Size of family unit
Related children under 18 years old
None One Two Three Four Five Six Seven
One person (unrelated
individual) . . . . . . . . . . . . . 8501
Under 65 years old . . . . 8667 8667
65 years old
and over . . . . . . . . . . . . 7990 7990
Two people . . . . . . . . . . . . . 10869
Householder under 65
years old . . . . . . . . . . . . 11214 11156 11483
Householder 65 years
old and over . . . . . . . . . 10075 10070 11440
Three people . . . . . . . . . . . 13290 13032 13410 13423
Four people . . . . . . . . . . . . 17029 17184 17465 16895 16954
Five people . . . . . . . . . . . . . 20127 20723 21024 20380 19882 19578
Six people . . . . . . . . . . . . . . 22727 23835 23930 23436 22964 22261 21845
Seven people . . . . . . . . . . . 25912 27425 27596 27006 26595 25828 24934 23953
Eight people . . . . . . . . . . . . 28967 30673 30944 30387 29899 29206 28327 27412 27180
Nine people or more . . . . . 34417 36897 37076 36583 36169 35489 34554 33708 33499 32208
Income deficit. Income deficit represents the difference between the total income of families
and unrelated individuals below the poverty level and their respective poverty thresholds. In
computing the income deficit, families reporting a net income loss are assigned zero dollars and
for such cases the deficit is equal to the poverty threshold.
This measure provides an estimate of the amount which would be required to raise the incomes of
all poor families and unrelated individuals to their respective poverty thresholds. The income
deficit is thus a measure of the degree of the impoverishment of a family or unrelated individual.
However, please use caution when comparing the average deficits of families with different
characteristics. Apparent differences in average income deficits may, to some extent, be a
function of differences in family size.
Aggregate income deficit. Aggregate income deficit refers only to those families or unrelated
individuals who are classified as below the poverty level. It is defined as the group (e.g., type of
family) sum total of differences between the appropriate threshold and total family income or total
personal income. Aggregate income deficit is subject to rounding, which means that all cells in a
matrix are rounded to the nearest hundred dollars. (For more information, see ‘‘Aggregate’’ under
Mean income deficit. Mean income deficit represents the amount obtained by dividing the total
income deficit for a group below the poverty level by the number of families (or unrelated
individuals) in that group. (The aggregate used to calculate mean income deficit is rounded.
For more information, see ‘‘Aggregate income deficit.’’) As mentioned above, please use caution
when comparing mean income deficits of families with different characteristics, as apparent
differences may to some extent be a function of differences in family size. Mean income deficit is
rounded to the nearest whole dollar. (For more information on means, see ‘‘Derived Measures.’’)
Comparability. The poverty definition used in the 1980 census and later differed slightly from
the one used in the 1970 census. Three technical modifications were made to the definition used
in the 1970 census:
1. Beginning with the 1980 census, the Office of Management and Budget eliminated any
distinction between thresholds for ‘‘families with a female householder with no husband
present’’ and all other families. The new thresholds — which apply to all families regardless of
the householder’s sex — were a weighted average of the old thresholds.
2. The Office of Management and Budget eliminated any differences between farm families and
nonfarm families, and farm and nonfarm unrelated individuals. In the 1970 census, the farm
thresholds were 85 percent of those for nonfarm families; whereas, in 1980 and later, the
same thresholds were applied to all families and unrelated individuals regardless of residence.
3. The thresholds by size of family were extended from seven or more people in 1970 to nine or
more people in 1980 and later.
These changes resulted in a minimal increase in the number of poor at the national level. For a
complete discussion of these modifications and their impact, see U.S. Census Bureau, Current
Population Reports, ‘‘Characteristics of the Population Below the Poverty Level: 1980,’’ P-60, No.
With respect to poverty, the population covered in the 1970 census was almost the same as that
covered in the 1980 census and later. The only difference was that in 1980 and after, unrelated
individuals under 15 years old were excluded from the poverty universe, while in 1970, only
those under age 14 were excluded. The limited poverty data from the 1960 census excluded all
people in group quarters and included all unrelated individuals regardless of age. It was unlikely
that these differences in population coverage would have had significant impact when comparing
the poverty data for people since the 1960 census.
Current Population Survey. Because the questionnaires and data collection procedures differ,
Census 2000 estimates of the number of people below the poverty level by various characteristics
may differ from those reported in the March 2000 Current Population Survey. Please refer to
www.census.gov/hhes/income/guidance.html for more details.
Data Source: 2000 Decennial Census Summary File 3