Measures of income USA dispersion

Selected Measures of Household Income Dispersion 2009
Income in 2009 adjusted dollars. For further explanation of income inequality measures, see Current Population Reports, Series P60-204, The
Changing Shape of the Nation’s Income Distribution: 1998. For information on confdentiality protection, sampling error, nonsampling error, and defnitions,
see www.census.gov/apsd/techdoc/cps/cpsmar10.pdf)

Measures of income USA dispersion in years 2009

MEASURE Household Income at Selected Percentiles
10th percentile limit = 12,120
20th percentile limit = 20,453
50th (median) = 49,777
80th percentile limit = 100,000
90th percentile limit = 137,632
95th percentile limit = 180,001

Household Income Ratios of Selected Percentiles
90th/10th = 11.36
95th/20th = 8.80
95th/50th = 3.62
80th/50th = 2.01
80th/20th = 4.89
20th/50th = 0.41

Mean Household Income of Quintiles
Lowest quintile = 11,552
Second quintile = 29,257
Third quintile = 49,534
Fourth quintile = 78,694
Highest quintile = 170,844

Shares of Household Income of Quintiles
Lowest quintile = 3.4
Second quintile = 8.6
Third quintile = 14.6
Fourth quintile = 23.2
Highest quintile = 50.3

Summary Measures Gini index of income inequality 0.468
Mean logarithmic deviation of
income = 0.550
Theil = 0.403
Atkinson:
e=0.25 = 0.097
e=0.50 = 0.190
e=0.75 = 0.288
STANDARD ERROR
Household Income at Selected
Percentiles
10th percentile limit = 85
20th percentile limit = 107
50th (median) = 213
80th percentile limit = 311
90th percentile limit = 638
95th percentile limit = 879

Household Income Ratios of Selected Percentiles
90th/10th = 0.095
95th/20th = 0.063
95th/50th = 0.022
80th/50th = 0.010
80th/20th = 0.030
20th/50th = 0.003

Mean Household Income of Quintiles
Lowest quintile = 42
Second quintile = 36
Third quintile = 47
Fourth quintile = 76
Highest quintile = 841

Shares of Household Income of Quintiles
Lowest quintile = 0.02
Second quintile = 0.06
Third quintile = 0.10
Fourth quintile = 0.15
Highest quintile = 0.33

Summary Measures
Gini index of income inequality 0.0028
Mean logarithmic deviation of
income = 0.0064
Theil = 0.0001
Atkinson:
e=0.25 = 0.0011
e=0.50 = 0.0018
e=0.75 = 0.0024
See footnotes at end of table.

1. Medians are calculated using $2,500 income intervals. Beginning with 2009 income data, the Census Bureau expanded the upper income intervals used to calculate medians to
$250,000 or more. Medians falling in the upper open-ended interval are plugged with “$250,000.” Before 2009, the upper open-ended interval was $100,000 and a plug of “$100,000” was
used.
2. Data have been revised to refect a correction to the weights in the 2005 ASEC.
3. Implementation of a 28,000 household sample expansion.
4. Implementation of Census 2000-based population controls.
5. Full implementation of 1990 census-based sample design and metropolitan defnitions, 7,000 household sample reduction, and revised editing of responses on race.
6. Introduction of 1990 census sample design.
7. Data collection method changed from paper and pencil to computer-assisted interviewing. In addition, the 1994 ASEC was revised to allow for the coding of different income amounts
on selected questionnaire items. Limits either increased or decreased in the following categories: earnings limits increased to $999,999; social security limits increased to $49,999;
supplemental security income and public assistance limits increased to $24,999; veterans’ benefts limits increased to $99,999; child support and alimony limits decreased to $49,999.
8. Implementation of 1990 census population controls.
9. Implementation of a new CPS ASEC processing system.
10. Recording of amounts for earnings from longest job increased to $299,999. Full implementation of 1980 census-based sample design.
11. Implementation of Hispanic population weighting controls and introduction of 1980 census-based sample design.
12. Implementation of 1980 census population controls. Questionnaire expanded to allow the recording of up to 27 possible values from a list of 51 possible sources of income.
13. First year medians were derived using both Pareto and linear interpolation. Before this year, all medians were derived using linear interpolation.
14. Some of these estimates were derived using Pareto interpolation and may differ from published data, which were derived using linear interpolation.
15. Implementation of a new CPS ASEC processing system. Questionnaire expanded to ask 11 income questions.
16. Full implementation of 1970 census-based sample design.
17. Introduction of 1970 census sample design and population controls.
18. Implementation of a new CPS ASEC processing system.
Source: U.S. Census Bureau, Current Population Survey, 1968 to 2010 Annual Social and Economic Supplements.