1. Take advantage of the availability of 1-year and 3-year period estimates for public use microdata areas, which include about 100,000 people, to assist with analyses for smaller areas.

  2. Take care to label ACS estimates, including those for 1 year, 3 years, and 5 years, as period estimates.

  3. Use ACS 3- and 5-year period estimates for income, housing value, and housing costs with care. To compensate for the differing time periods for which dollar amounts are collected, those amounts are adjusted to a common calendar year by the change in the national consumer price index. This inflation adjustment expresses all of the reported dollar amounts in a comparable manner with regard to purchasing power as of the most recent calendar year in the period. However, the resulting estimates should not be interpreted as current-year estimates.

  4. Use care in comparing ACS estimates with estimates from other data sources, including the 2000 long-form sample and other surveys, and be cognizant of the differences that could affect the comparisons. Such differences may include population coverage, sample size and design, reference periods, residence rules, and interview modes.


The panel strongly supports the ACS, but it does not underestimate the challenges facing the Census Bureau, which must produce a flood of data products every year, or the challenges facing the user community. The continuous ACS design will ultimately support not only current applications, but also new applications requiring innovative data products. However, there will be a learning curve. For a successful transition that leads to the full use of the ACS, the panel makes five overarching recommendations (identified by chapter number) to the Census Bureau on investment in the ACS, increasing the precision of ACS estimates, a user education and outreach program, priorities for research and development, and looking to the future.

Recommendation 7-1: The Census Bureau should continue to make sufficient funding of the ACS one of its top priorities. It should seek adequate funding on a continuing basis, not only for data collection and production, but also for ongoing programs of methodological research and evaluation and user outreach and education.

Recommendation 4-4: The Census Bureau should identify potential ways to increase the precision of ACS estimates for small geographic ar-

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