While both categories of geographic units, legal/administrative entities and statistical entities, serve the common purpose of presenting Census Bureau data, the concepts, principles, and criteria for recognizing the entities in each category involve different preparations by the Census Bureau. For both categories, it is critical that the Census Bureau establish and implement standards, guidelines, and criteria for defining, identifying, and delineating the geographic entities it recognizes for each census and sample survey. When the Census Bureau agrees to tabulate information for a new kind of geographic area, it must specify precise criteria for establishing the new component entities. These standards must be somewhat flexible in order to accommodate new trends and developments, yet they also must present a sturdy, consistent application of methodology and criteria that have proven themselves over time.
The status of legal/administrative entities generally is well defined. Legislation or administrative measures create them, specify their governmental or administrative functions, and contain provisions for establishing and changing their names and boundaries. Once the Census Bureau is convinced that a particular category of governmental unit is appropriate for data presentation, it:
- Ascertains the existence of the applicable units by making inquiries of relevant government agencies.
- Identifies an authoritative source of information about entities.
- Obtains names, establishes codes, and locates boundaries for entities.
- Enters this information into the TIGER data base, classifying it to correspond to entity boundaries.
- Presents accurate results for the governmental units in the appropriate data tabulations and presentations.
A similar set of operations applies to statistical entities, but there is an important difference. Once the Census Bureau justifies the need for a new type of geographic area in terms of various principles, it must establish
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