Income

Guidance About Income Sources

The Census Bureau reports income estimates from several major national household surveys and programs:

• Annual Social and Economic Supplement to the Current Population Survey (CPS ASEC)
• American Community Survey (ACS)
• Survey of Income and Program Participation (SIPP)
• Census 2000 long form
• Small Area Income and Poverty Estimates program (SAIPE)

Each of these surveys differs from the others in some ways, such as the length and detail of its questionnaire, the number of households included (sample size), and the methodology used to collect and process the data. The Small Area Income and Poverty Estimates program uses statistical models to produce income and poverty estimates by combining survey results with administrative records.

As a result of this multiplicity of sources, it is important to understand that different surveys and methods, which are designed to meet different needs, also produce different results.

Which Data Source To Use

The CPS ASEC is the preferred source for national analysis (see chart shown below). It provides the most timely and most accurate cross-section data for the nation on income and poverty and is the official source of national poverty estimates. The ACS is preferred for subnational data on income and poverty by detailed demographic characteristics, because of its large sample size. The Census Bureau recommends using the ACS for single-year estimates of income and poverty at the state level. (Users looking for consistent state-level trends before 2006 should use the CPS ASEC.) The following materials provide more information on income data from the CPS ASEC and ACS.

• Comparison of Household Income: ACS 2008 and CPS ASEC 2008 and 2009 Two-Year Averages [XLS - 21k]
• Evaluation of Median Income and Earnings Estimates: A Comparison of the American Community Survey and the Current Population Survey [PDF - 48k]
• Fact Sheet on Differences Between CPS ASEC and ACS Data For Income and Poverty

For substate areas, like counties, users should consider their specific needs when picking the appropriate data source. The SAIPE program produces overall poverty and household income single-year estimates with standard errors usually smaller than direct survey estimates. Users looking to compare estimates of the number and percentage of people in poverty for counties or school districts or the median household income for counties should use SAIPE, especially if the population is less than 65,000. Users who need other characteristics such as poverty among Hispanics or median earnings, should use the ACS, where and when available.

The SIPP is focused on collecting accurate longitudinal income and program participation data to help understand the dynamics of a household’s economic situation. Its timeliness is not comparable since one must wait until after a 3- or 4-year panel has concluded to analyze the longitudinal data.

The chart below summarizes the recommendations at various geographic levels:

Notes:

• CPS ASEC: Current Population Survey Annual Social and Economic Supplement
• ACS: American Community Survey
• SAIPE: Small Area Income and Poverty Estimates
• SIPP: Survey of Income and Program Participation
• Census 2000: Census 2000