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Small Area Income & Poverty EstimatesIntercensal Estimates for States, Counties & School Districts |
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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:
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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, economic data from the BEA and the most recent census. These estimates are then combined with direct estimates based on the CPS 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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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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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 American Community Survey (ACS) in models for small area income and poverty estimates. Since the ACS income and poverty estimates will not be available on a nationwide basis until 2006 (for data collected in calendar year 2005), we have begun our research using estimates from the Census 2000 Supplementary Survey (C2SS).We strongly believe that using information from the C2SS, the 2001 and 2002 Supplementary Surveys, and the ACS will improve the income and poverty estimates.
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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 go to A Basic Explanation of Confidence Intervals in our "State and County Estimates" section. For information on confidence intervals of the difference between two estimates, please go to General Cautions about Comparisons of Estimates in our "Documentation" section.
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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. By collecting income and poverty data in larger surveys, such as the American Community Survey, we will improve direct sample survey estimates of income and poverty, the role currently played by the CPS data, in the models. We expect the American Community Survey data to be available for this role around 2006. 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.
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Estimates are made using survey and administrative data that are not available until several years after the year to which they refer. For example, until recently, the food stamp data needed to make the reference year estimates were not available until three years later. Recent improvements in processing the food stamp data allows for earlier delivery, reducing the lag to two years. We plan to release estimates for income year 2002 in November 2004.
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Prior to 1998, 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.
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Challenges to state, county, or school district estimates from the SAIPE program must be submitted in writing to Dr. Daniel Weinberg, Chief, Housing and Household Economic Statistics Division, via mail to U.S. Census Bureau, Room 1462-3, Washington, DC 20233-8500, via facsimile to 301-457-6813, or via email to hhes.saipe@census.gov. 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 submitted 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 US Census Bureau will attempt to resolve your challenge within 30 days of receipt and will notify you if it will take longer.
NOTE: The challenge period for income year 2000 estimates has ended.
For complete details of the challenge process and what challenges will result in revised estimates see
Challenge Procedures for Estimates.
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The Statistical Information Staff of the Housing and Household Economic Statistics Division is available to answer your general questions: contact them at 301-763-3242 or visit ask.census.gov.
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