Data Dictionary: ACS 2006 -- 2008 (3-Year Estimates)
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Data Source: U.S. Census Bureau
Table: B17024. Age By Ratio Of Income To Poverty Level In The Past 12 Months [131]
Universe: Universe: Population for whom poverty status is determined
Table Details
B17024. Age By Ratio Of Income To Poverty Level In The Past 12 Months
Universe: Universe: Population for whom poverty status is determined
Variable Label
B17024001
B17024002
B17024003
B17024004
B17024005
B17024006
B17024007
B17024008
B17024009
B17024010
B17024011
B17024012
B17024013
B17024014
B17024015
B17024016
B17024017
B17024018
B17024019
B17024020
B17024021
B17024022
B17024023
B17024024
B17024025
B17024026
B17024027
B17024028
B17024029
B17024030
B17024031
B17024032
B17024033
B17024034
B17024035
B17024036
B17024037
B17024038
B17024039
B17024040
B17024041
B17024042
B17024043
B17024044
B17024045
B17024046
B17024047
B17024048
B17024049
B17024050
B17024051
B17024052
B17024053
B17024054
B17024055
B17024056
B17024057
B17024058
B17024059
B17024060
B17024061
B17024062
B17024063
B17024064
B17024065
B17024066
B17024067
B17024068
B17024069
B17024070
B17024071
B17024072
B17024073
B17024074
B17024075
B17024076
B17024077
B17024078
B17024079
B17024080
B17024081
B17024082
B17024083
B17024084
B17024085
B17024086
B17024087
B17024088
B17024089
B17024090
B17024091
B17024092
B17024093
B17024094
B17024095
B17024096
B17024097
B17024098
B17024099
B17024100
B17024101
B17024102
B17024103
B17024104
B17024105
B17024106
B17024107
B17024108
B17024109
B17024110
B17024111
B17024112
B17024113
B17024114
B17024115
B17024116
B17024117
B17024118
B17024119
B17024120
B17024121
B17024122
B17024123
B17024124
B17024125
B17024126
B17024127
B17024128
B17024129
B17024130
B17024131
Relevant Documentation:
Excerpt from: Social Explorer; U.S. Census Bureau; American Community Survey 2006-2008 Summary File: Technical Documentation.
 
Age
The data on age were derived from answers to Question 4. The age classification is based on the age of the person in complete years at the time of interview. Both age and date of birth are used in combination to calculate the most accurate age at the time of the interview. Inconsistently reported and missing values are assigned or imputed based on the values of other variables for that person, from other people in the household, or from people in other households ("hot deck" imputation). Data on age are used to determine the applicability of other questions for a particular individual and to classify other characteristics in tabulations. Age data are needed to interpret most social and economic characteristics used to plan and analyze programs and policies. Therefore, age data are tabulated by many different age groupings, such as 5-year age groups.
Median Age
The median age is the age that divides the population into two equal-size groups. Half of the population is older than the median age and half is younger. Median age is based on a standard distribution of the population by single years of age and is shown to the nearest tenth of a year. (See the sections on "Standard Distributions" and "Medians" under "Derived Measures.")
Age Dependency Ratio
The age dependency ratio is derived by dividing the combined under-18 and 65-and-over populations by the 18-to-64 population and multiplying by 100.
Old-Age Dependency Ratio
The old-age dependency ratio is derived by dividing the population 65 years and over by the 18-to-64 population and multiplying by 100.
Child Dependency Ratio
The child dependency ratio is derived by dividing the population under 18 years by the 18-to-64 population, and multiplying by 100.
Limitation of the Data
Caution should be taken when comparing population in age groups across time. The entire population continually ages into older age groups over time and babies fill in the youngest age group. Therefore, the population of a certain age is made up of a completely different group of people in 2000 and 2008. Since populations occasionally experience booms/increases and busts/decreases in births, deaths, or migration (for example, the postwar Baby Boom from 1946-1964), one should not necessarily expect that the population in an age group in Census 2000 should be similar in size or proportion to the population in the same age group in the 2008 ACS. For example, Baby Boomers were age 36 to 54 in Census 2000 while they were age 44 to 62 in the 2008 ACS. Therefore, the age group 55 to 59 would show a considerable increase in population when comparing Census 2000 data with the 2008 ACS data. Beginning in 2006, the population in group quarters (GQ) is included in the ACS. Some types of GQ populations have age distributions that are very different from the household population. The inclusion of the GQ population could therefore have a noticeable impact on the age distribution. This is particularly true for areas with a substantial GQ population.
Question/Concept History
The 1996-2002 American Community Survey question asked for month, day, and year of birth before age. Since 2003, the American Community Survey question asked for age, followed by month, day, and year of birth. In 2008, an additional instruction was provided with the age and date of birth question on the American Community Survey questionnaire to report babies as age 0 when the child was less than 1 year old. The addition of this instruction occurred after 2005 National Census Test results indicated increased accuracy of age reporting for babies less than one year old.
Excerpt from: Social Explorer; U.S. Census Bureau; American Community Survey 2006-2008 Summary File: Technical Documentation.
 
Ratio
This is a measure of the relative size of one number to a second number expressed as the quotient of the first number divided by the second. For example, the sex ratio is calculated by dividing the total number of males by the total number of females, and then multiplying by 100.



Excerpt from: Social Explorer; U.S. Census Bureau; American Community Survey 2006-2008 Summary File: Technical Documentation.
 
Poverty Status in the Past 12 Months
Poverty statistics in ACS products adhere to the standards specified by the Office of Management and Budget in Statistical Policy Directive 14. The Census Bureau uses a set of dollar value thresholds that vary by family size and composition to determine who is in poverty. Further, poverty thresholds for people living alone or with nonrelatives (unrelated individuals) vary by age (under 65 years or 65 years and older). The poverty thresholds for two-person families also vary by the age of the householder. If a familys total income is less than the dollar value of the appropriate threshold, then that family and every individual in it are considered to be in poverty. Similarly, if an unrelated individual's total income is less than the appropriate threshold, then that individual is considered to be in poverty.
How the Census Bureau Determines Poverty Status
In determining the poverty status of families and unrelated individuals, the Census Bureau uses thresholds (income cutoffs) arranged in a two-dimensional matrix. The matrix consists of family size (from one person to nine or more people) cross-classified by presence and number of family members under 18 years old (from no children present to eight or more children present). Unrelated individuals and two-person families are further differentiated by age of 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 in the last 12 months with the poverty threshold appropriate for that person's family size and composition (see example below). If the total income of that person's family is less than the threshold appropriate for that family, then the person is considered "below the poverty level,"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. The total number of people below the poverty level is the sum of people in families and the number of unrelated individuals with incomes in the last 12 months below the poverty threshold.

Since ACS is a continuous survey, people respond throughout the year. Because the income questions specify a period covering the last 12 months, the appropriate poverty thresholds are determined by multiplying the base-year poverty thresholds (1982) by the average of the monthly inflation factors for the 12 months preceding the data collection. See the table below titled "Poverty Thresholds in 1982," by "Size of Family and Number of Related Children Under 18 Years (Dollars)," for appropriate base thresholds. See the table "The 2008 Poverty Factors" for the appropriate adjustment based on interview month.

For example, consider a family of three with one child under 18 years of age, interviewed in July 2008 and reporting a total family income of $14,000 for the last 12 months (July 2007 to June 2008). The base year (1982) threshold for such a family is $7,765, while the average of the 12 inflation factors is 2.19359. Multiplying $7,765 by 2.19359 determines the appropriate poverty threshold for this family type, which is $17,033. Comparing the familys income of $14,000 with the poverty threshold shows that the family and all people in the family are considered to have been in poverty. The only difference for determining poverty status for unrelated individuals is that the person's individual total income is compared with the threshold rather than the familys income.

For example, consider a family of three with one child under 18 years of age, interviewed in July 2008 and reporting a total family income of $14,000 for the last 12 months (July 2007 to June 2008). The base year (1982) threshold for such a family is $7,765, while the average of the 12 inflation factors is 2.19359. Multiplying $7,765 by 2.19359 determines the appropriate poverty threshold for this family type, which is $17,033. Comparing the familys income of $14,000 with the poverty threshold shows that the family and all people in the family are considered to have been in poverty. The only difference for determining poverty status for unrelated individuals is that the person's individual total income is compared with the threshold rather than the familys income.
The 2008 Poverty Factors:
Interview Month Poverty Factors
January 2.14841
February 2.15589
March 2.16297
April 2.17003
May 2.17705
June 2.18455
July 2.19359
August 2.20366
September 2.21330
October 2.22219
November 2.22879
December 2.23073

Poverty Thresholds in 1982, by Size of Family and Number of Related Children Under 18 Years Old (Dollars)
Size of family unit Related children under 18 years
None One Two Three Four Five Six Seven Eight or more
One person (unrelated individual)                  
Under 65 years 5,019                
65 years and over 4,626                
Two persons                  
Householder under 65 years 6,459 6,649              
Householder 65 years and over 5,831 6,624              
Three persons 7,546 7,765 7,772            
Four persons 9,950 10,112 9,783 9,817          
Five persons 11,999 12,173 11,801 11,512 11,336        
Six persons 13,801 13,855 13,570 13,296 12,890 12,649      
Seven persons 15,879 15,979 15,637 15,399 14,955 14,437 13,869    
Eight persons or more 17,760 17,917 17,594 17,312 16,911 16,403 15,872 15,738  
Nine persons or more 21,364 21,468 21,183 20,943 20,549 20,008 19,517 19,397 18,649


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 were excluded from the numerator and denominator when calculating poverty rates.
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 thresholds. These specified poverty levels are obtained by multiplying the official thresholds by the appropriate factor. Using the previous example cited (a family of three with one related child under 18 years responding in July 2008), the dollar value of 125 percent of the poverty threshold was $ 21,291 ($ 17,033x 1.25).
Income Deficit
Income deficit represents the difference between the total income in the last 12 months 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 "Derived Measures.")
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.")
Question/Concept History
Derivation of the Current Poverty Measure
When the original poverty definition was developed in 1964 by the Social Security Administration (SSA), 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, that is, 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 USDAs 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 total family income. These dollar figures, with some adjustments, later became the official poverty thresholds. Since the Economy Food Plan budgets varied by family size and composition, so too did the poverty thresholds. For two-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 two-person families. The poverty thresholds are revised annually to allow for changes in the cost of living as reflected in the Consumer Price Index for All Urban Consumers (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 .
Comparability
Because of differences in survey methodology (questionnaire design, method of data collection, sample size, etc.), the poverty rate estimates obtained from American Community Survey data may differ from those reported in the Current Population Survey, Annual Social and Economic Supplement, and those reported in Census 2000. Please refer to http://www.census.gov/hhes/www/poverty/newguidance.html for more details.
Poverty Status of Households in the Past 12 Months
Since poverty is defined at the family level and not the household level, the poverty status of the household is determined by the poverty status of the householder. Households are classified as poor when the total income of the householder's family in the last 12 months is below the appropriate poverty threshold. (For nonfamily householders, their own income is compared with the appropriate threshold.) The income of people living in the household who are unrelated to the householder is not considered when determining the poverty status of a household, nor does their presence affect the family size in determining the appropriate threshold. The poverty thresholds vary depending upon three criteria: size of family, number of children, and, for one- and two- person families, age of the householder.
Limitation of the Data
Beginning in 2006, the population in group quarters (GQ) is included in the ACS. The part of the group quarters population in the poverty universe (for example, people living in group homes or those living in agriculture workers dormitories) is many times more likely to be in poverty than people living in households. Direct comparisons of the data would likely result in erroneous conclusions about changes in the poverty status of all people in the poverty universe.