In tabulating data, the Census Bureau is concerned with the individual’s right to confidentiality. Specifically, Federal law (Title 13, U.S. Code) states that:
- The information gathered by the Census Bureau is solely for statistical purposes.
- The publication of the data must be such that neither individual establishments nor people nor their residences can be identified.
- Only sworn officers and employees of the Census Bureau may examine
individual responses. All geographic statistical entities must be defined and delineated to comply with the legal requirements and the policies specified by the Census Bureau to protect the confidentiality of the collected information. These concerns are not restricted to the geographic classification component of a census or sample survey.
To provide a national structure that supports the first requirement, the Census Bureau devises geographic entities that serve as the statistical equivalents of some legal entities in order to supplement, but not to replace, governmental units. To meet the second requirement, the Census Bureau structures the criteria for the various statistical entities to ensure appropriate population size thresholds. These size criteria generally permit the Census Bureau to provide meaningful demographic and economic data, and at the same time ensure confidentiality through sufficient numbers of responses within a particular geographic entity. In this way, the geographic area criteria support both the Census Bureau’s confidentiality mandate and the statistical validity goal by limiting the minimum population size of most subcounty statistical entities.
Several technical considerations affect the data presentation for geographic entities. The Census Bureau must (1) ensure that each level of geography becomes a part of the geographic hierarchy, (2) establish a numeric coding scheme to correspond with the names of the entities, and (3) ensure that
