Part Six: How We Will Know Whether the Count Was Accurate

No census can be compared with a perfect list of everyone who should have been counted. Census must instead use independent statistical methods to estimate how many people were missed, counted more than once, or counted in the wrong place.

The Census Bureau plans to continue its two principal coverage-measurement programs for 2030. Demographic Analysis will build population estimates from sources such as birth, death, immigration, and Medicare records. Coverage Estimation will compare the census with a second system of person and housing-unit information and use dual-system estimation to measure undercounts, overcounts, and other coverage errors. Both are designed to operate independently from the enumeration they are evaluating.

Coverage measurement does not correct the official census results. Its purpose is to help the public understand their strengths and limitations and to guide improvements to later population estimates and future censuses. That makes the design of the evaluation especially important. Communities may suspect that people were missed, but without credible independent estimates, they may be unable to demonstrate the extent or distribution of the problem.

This part examines whether the redesigned system will remain independent enough to detect the weaknesses of a more administrative-record-driven census and whether it will produce estimates detailed enough to identify unequal coverage across communities.