A relatively permanent statistical subdivision of a county, tracts are delineated by a local committee of census data users and approved by the Census Bureau. These small, relatively homogeneous areas are designed to be similar in population characteristics, economic status, and living conditions. Ideally, a designated area contains between 1,200 and 8,000 people, with an optimum size of 4,000 persons. For example, an urban area might be divided into multiple of these statistical areas, each representing a distinct neighborhood with identifiable socioeconomic traits.
The establishment of these geographic entities allows for detailed analysis of population distribution and demographic trends at a localized level. This localized information aids in urban planning, resource allocation, and policy development by providing a framework for understanding spatial variations within a larger region. Historically, the consistent availability of this data over time allows researchers and policymakers to track changes and assess the impact of various interventions or events on specific communities.