5-year American Community Survey estimates of socioeconomic variables at the tract level released in 2012. The TIGER/Line Files are shapefiles and related database files (.dbf) that are an extract of selected geographic and cartographic information from the U.S. Census Bureaus Master Address File / Topologically Integrated Geographic Encoding and Referencing (MAF/TIGER) Database (MTDB). The MTDB represents a seamless national file with no overlaps or gaps between parts, however, each TIGER/Line File is designed to stand alone as an independent data set, or they can be combined to cover the entire nation. Census tracts are small, relatively permanent statistical subdivisions of a county or equivalent entity, and were defined by local participants as part of the 2010 Census Participant Statistical Areas Program. The Census Bureau delineated the census tracts in situations where no local participant existed or where all the potential participants declined to participate. The primary purpose of census tracts is to provide a stable set of geographic units for the presentation of census data and comparison back to previous decennial censuses. Census tracts generally have a population size between 1,200 and 8,000 people, with an optimum size of 4,000 people. When first delineated, census tracts were designed to be homogeneous with respect to population characteristics, economic status, and living conditions. The spatial size of census tracts varies widely depending on the density of settlement. Physical changes in street patterns caused by highway construction, new development, and so forth, may require boundary revisions. In addition, census tracts occasionally are split due to population growth, or combined as a result of substantial population decline. Census tract boundaries generally follow visible and identifiable features. They may follow legal boundaries such as minor civil division (MCD) or incorporated place boundaries in some States and situations to allow for census tract-to-governmental unit relationships where the governmental boundaries tend to remain unchanged between censuses. State and county boundaries always are census tract boundaries in the standard census geographic hierarchy. In a few rare instances, a census tract may consist of noncontiguous areas. These noncontiguous areas may occur where the census tracts are coextensive with all or parts of legal entities that are themselves noncontiguous. For the 2010 Census, the census tract code range of 9400 through 9499 was enforced for census tracts that include a majority American Indian population according to Census 2000 data and/or their area was primarily covered by federally recognized American Indian reservations and/or off-reservation trust lands; the code range 9800 through 9899 was enforced for those census tracts that contained little or no population and represented a relatively large special land use area such as a National Park, military installation, or a business/industrial park; and the code range 9900 through 9998 was enforced for those census tracts that contained only water area, no land area.The American Community Survey (ACS) 5 Year 2008-2012 socioeconomic information is a subset of information available for download. Downloaded tables include: B08013 - Aggregate Travel Time To Work Of Workers By Sex, B08303 - Travel Time To Work, B17019 - Poverty Status In The Past 12 Months Of Families By Household Type By Tenure, B17021 - Poverty Status Of Individuals In The Past 12 Months By Living Arrangement, B19001 - Household Income In The Past 12 Months, B19013 - Median Household Income In The Past 12 Months, B19025 - Aggregate Household Income In The Past 12 Months, B19113 - Median Family Income In The Past 12 Months, B19202 - Median Nonfamily Household Income In The Past 12 Months, B23001 - Sex By Age By Employment Status For The Population 16 Years And Over, B25014 - Tenure By Occupants Per Room, B25026 - Total Population in Occupied Housing Units by Tenure by year Householder Moved into Unit, B25106 - Tenure By Housing Costs As A Percentage Of Household Income In The Past 12 Months, C24010 - Sex By Occupation For The Civilian Employed Population 16 Years And Over, B20004 - Median Earnings In the Past 12 Months (In 2009 Inflation-Adjusted Dollars) by Sex by Educational Attainment for the Population 25 Years and Over, B23006 - Educational Attainment by Employment Status for the Population 25 to 64 Years and B24021 - Occupation By Median Earnings In The Past 12 Months (In 2012 Inflation-Adjusted Dollars) For The Full-Time, Year-Round Civilian Employed Population 16 Years And Over. Data is current as of 5/6/2015. This layer is intended for researchers, students, policy makers, and the general public for reference and mapping purposes, and may be used for basic applications such as viewing, querying, and map output production. This layer will provide a basemap for layers related to socio-political analysis, statistical enumeration and analysis, or to support graphical overlays and analysis with other spatial data. More advanced user applications may focus on demographics, urban and rural land use planning, socio-economic analysis and related areas (including defining boundaries, managing assets and facilities, integrating attribute databases with geographic features, spatial analysis, and presentation output.) United States. Department of Housing and Urban Development. (2015). ACS 5 Year Socioeconomic Data By Tract, 2008-2012. United States. Department of Housing and Urban Development. Available at http://purl.stanford.edu/sx060pc9679. To download additional socioeconomic information, visit: http://www.census.gov/acs/www/.
