U.S. Census Bureau

 Small Area Income & Poverty Estimates

 Model-based Estimates for States, Counties, & School Districts

Frequently Asked Questions about SAIPE


  1. What is SAIPE?
  2. How are the SAIPE program estimates constructed?
  3. What is the definition of poverty?
  4. Does the SAIPE program incorporate data from the American Community Survey (ACS)?
  5. What are confidence intervals? What do they mean?
  6. How can the SAIPE program's estimates be improved?
  7. Why is there a lag in releasing the SAIPE program estimates?
  8. Why are there no county-level SAIPE program estimates for income year 1996?
  9. What should I do if I believe a SAIPE program estimate is wrong?
  10. If I have further questions, whom should I contact?

  1. What is SAIPE?

    SAIPE is the Small Area Income and Poverty Estimates program of the U.S. Census Bureau. We produce model-based estimates annually of income and poverty for states, counties, and school districts. We do not produce projections or estimates for other geographic units such as towns, cities, or metro areas. The following estimates are produced:

    States and Counties:

    School districts:

    For more information, please see our Overview.

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  2. How are the SAIPE program estimates constructed?
    We use statistical models to create the estimates. The official state and county estimates of income and poverty come directly from the American Community Survey (ACS). The statistical models we use relate income and poverty to indicators based on summary data from federal income tax returns, data about participation in the Food Stamp program, data about Supplemental Security Income program recipiency rate, economic data from the Bureau of Economic Analysis (BEA) and the most recent census. These estimates are then combined with direct estimates from the ACS sample to provide figures which are more precise than either set alone. This is a standard method for making statistical estimates for small areas. We refer to the final combined estimates as "model-based."

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  3. What is the definition of poverty?

    Poverty status is defined by family; either everyone in the family is in poverty or no one in the family is in poverty. The characteristics of the family used to determine poverty status are: number of people, number of related children under 18, and whether the primary householder is over age 65. An income threshold is determined given a particular family's set of characteristics; if that family's income is below that threshold, the family is in poverty. For more information, please see Poverty.

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  4. Does the SAIPE program incorporate data from the American Community Survey (ACS)?

    Yes. In their final report, the National Academy of Sciences Panel on Estimates of Poverty for Small Geographic Areas (2000) recommended that the Census Bureau investigate using estimates from the ACS in models for small area income and poverty estimates. Full implementation of the ACS began in January 2005, and the SAIPE program incorporated those data into the 2005 estimates. All prior years of estimates were created using data from the Annual Social and Economic Supplement (ASEC) of the Current Population Survey (CPS).

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  5. What are confidence intervals? What do they mean?

    A confidence interval is a range of values that, with some level of certainty, contains the true value the estimate is approximating. For example, each state and county estimate is listed with a 90-percent confidence interval. This means that for a particular estimate, if we carried out our estimation procedure and created a confidence interval 100 times, the actual value that the estimate is approximating is in that interval approximately 90 out of the 100 times. For more details about confidence intervals, please check a basic explanation of confidence intervals. For information on confidence intervals of the difference between two estimates, please check the general cautions page.

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  6. How can the SAIPE program's estimates be improved?

    We see two ways to improve the statistical precision of the income and poverty estimates. First, by improving the models, and second, by improving the input data. We continue to explore and assess the utility of alternate model formulations and statistical approaches. The current estimation methods use administrative record sources uniformly available for the entire nation. If access to administrative record data at both the federal and state levels were expanded, we could add new variables, especially from state and local record systems, which would improve the accuracy of the model-based estimates. We welcome suggestions. Send your suggestions via email to hhes.saipe@census.gov.

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  7. Why is there a lag in releasing the SAIPE program estimates?

    Estimates are made using survey and administrative data that are not available until well after the year to which they refer. For example, the SAIPE program's 2004 estimates utilized federal tax return data for 2004, which were filed in 2005, and were available to our program in 2006. Recently, improvements in acquisition and processing of some of the inputs allowed for an earlier delivery.

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  8. Why are there no county-level SAIPE program estimates for income year 1996?

    Prior to release of income year 1998 data, county data were produced every two years, for odd-numbered years. The Improving America's Schools Act of 1994 required estimates of poverty for school districts every two years. Both state and county-level estimates are produced as the building blocks for these estimates. We began producing county estimates for even-numbered years in 1998 to meet the demand for more current county-level estimates. State-level estimates have been produced annually since 1995 to meet requirements of The Personal Responsibility and Work Opportunity Reconciliation Act of 1996. School district estimates are also produced annually as required by the No Child Left Behind Act of 2001.

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  9. What should I do if I believe a SAIPE program estimate is wrong?

    Challenges to state, county, or school district estimates from the SAIPE program must be submitted to Chief, Data Integration Division:

    In order for us to investigate your request, you must include the following information: 1) your name, mailing address, telephone number, fax number (if any), email address (if any), and organizational affiliation; 2) identification of the estimate you believe is incorrect; and 3) supporting evidence for the existence of an error. Challenges must be received within 90 days of the original release date. This time limit is necessary because the estimates are used in allocation formulas and must be finalized prior to their use in these formulas. The U.S. Census Bureau will attempt to resolve your challenge within 30 days of receipt and will notify you if it will take longer.

    For complete details of the challenge process and what challenges will result in revised estimates see Challenge Procedures for Estimates.

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  10. If I have further questions, whom should I contact?

    For assistance, please contact the Demographic Call Center Staff at 301-763-2422 or 1-866-758-1060 (toll free) or visit ask.census.gov for further information.

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Source: U.S. Census Bureau, Data Integration Division, Small Area Estimates Branch
For assistance, please contact the Demographic Call Center Staff at 301-763-2422 or 1-866-758-1060 (toll free) or visit ask.census.gov for further information.