The LTDB provides estimates using 2010 boundaries for a standard set of variables from 1970 through 2000. These data may meet the needs of many users. As an initial step, we provide two sets of files. The "full count" files include the key variables from Census 2010 (race and Hispanic origin, age by race and Hispanic origin, household composition, and housing occupancy and tenure), with comparable variables from the censuses in 1970-2000 and adjusted to 2010 boundaries. The "sample count" files include a wide range of other variables based on sample data -- the one-in-six samples from the decennial census in 1970-2000 and the sample data from the American Community Survey for 2006-2010. These include variables such as socioeconomic characteristics that are widely used by researchers.
On the LTDB download page you will find a codebook that identifies the original tables in each census year from which data have been taken. You will also find the standard harmonized data set for 1970-2010. For reference, we provide the five individual data files that include the original tract IDs and data for each decade. CLICK HERE for the download page.
The LTDB also includes other functions.
1. INPUT YOUR OWN DATA . If you have data aggregated to census tract boundaries for any of the decades 1970-2000, you can use LTDB tools to estimate these data within 2010 boundaries.
2. BACKWARDS LTDB . If you have 2010 data that you want to analyze along with other data for 2000, you can use this tool to convert backwards. This system provides a STATA program and a crosswalk file that links the 2000 and 2010 boundaries. You must provide your own 2010 data in STATA format. Consult the "INPUT YOUR OWN DATA" SECTION to learn how to use the STATA file and what issues to be aware of.