We are pleased to announce the release of a new consolidated master index for the U.S. Census 2010 Summary File 1 (SF1) and American Community Survey (ACS) 5 Year datasets. The files and documentation are the result of a voluntary effort of Dr. Michael Greenwald (personal) and Jonathan Brooks (Texas A&M Transportation Institute) and are available free of charge via the web address below: http://tti.tamu.edu/group/transit-mobility/sf1acsindex/ What is the challenge the index files address? The U.S. Census Bureau publishes wonderfully rich data products based on the Decennial Census and American Community Survey. They also provide high-quality geographic datasets through the TIGER geography program. SF1, ACS, and TigerLine datasets all have identification fields; such as FIPS code, LOGRECNO number, or name field. Unfortunately, no common identification field is available that is capable of linking the three datasets out-of-the-box. For example: In Lane County, Oregon the record index value for Census Block Group 1 in Census Tract 1 is 119370 for 2010 SF1 datasets, but for ACS datasets the same Block Group is number 4514 (ACS 2006-2010) or 4513 (ACS 2007-2011). The master index files solve this data interoperability challenge. How do the index files overcome the data-linking challenge? The master index files act as an intermediate between TIGER, SF1 and ACS datasets. Each consolidated index file contains record identifier numbers from 2010 Census SF1, the 2006-2010 ACS, the 2007-2011 ACS, and FIPS location codes for Census Tracts, Census Block Groups, and even Census Block geographies. The index files are stored in comma-delimited format and as such are compatible with many types of software (e.g. Microsoft Excel, Microsoft Access, SAS, SPSS, ArcGIS, etc.). You can use the same consolidated master index to connect the records from the SF1, the ACS 2006-2010 or the ACS 2007-2010 to their correct Census Tract, Census Block Group or Census Block! Simply connect your Census datasets to the master index file and then join up to another dataset. Please note that the index files do not contain any population or demographic data of any kind; they are simply for linking between disparate datasets. The normal Census Bureau warnings about comparing SF1 Decennial Census data and ACS sample data still apply. There is a consolidated index file for each state, Washington DC, and Puerto Rico. The files are available as a whole or by state via the website. Who would find these files useful? Professionals working with TIGER geographies and population/demographic data from the Census Bureau may find the master index files to be a useful tool for linking datasets; such as: * Transportation or Land Use Planners; * GIS Technicians; * Public Health Officials; * Economists; and * Demographers. Who produced the files? Where can I download/learn more? The index files and accompanying documentation are the result of a voluntary effort of Dr. Michael Greenwald (personal) and Jonathan Brooks (Texas A&M Transportation Institute). Texas A&M Transportation Institute is voluntarily providing a home to the files and is in no way responsible for the accuracy of or use of the files. http://tti.tamu.edu/group/transit-mobility/sf1acsindex/ What if I still have questions? Please contact Dr. Michael J. Greenwald via e-mail (michael.j.greenwald@gmail.com<mailto:michael.j.greenwald@gmail.com>). Dr. Greenwald will respond as time constraints allow. Jonathan P. Brooks. Associate Transportation Researcher Transit Mobility Program Texas A&M Transportation Institute 701 N Post Oak Rd, Suite 430 Houston, TX 77063 Tel 713.613.9206 | Cell 806.440.2462 http://tti.tamu.edu/group/transit-mobility [cid:image001.jpg@01CE2716.2800ADE0]