I am working with Arcmap 10.1 and census tract level data for 1990 and 2011. I am trying to compare different options for tracking changes between the tracts.

The tracts change between the census polls, and there are some tracts from 1990 that merged to form a single tract in 2011, and those that split up.

I would like to know what are some options I have to keep track of the changes in the tracts and how I can compare demographic changes from 1990 to 2011?


The Census Bureau has prepared so-called "Relationship Files" that describe the geographic relationships between geographies (including tracts) at different times. This includes a lot of information for going between the two datasets by population or land area (a complete list is below).

In your case, since you're trying to go from 1990 to 2010, you will have to use the 1990 to 2000 relationship files and the 2000 to 2010 relationship files in tandem. I would recommend trying out each set of files individually before creating a combined workflow.

Relationship file fields


The Census Bureau's "relationship files" (specifically the "Geographic Relationships Over Time (Comparability)" for Census Tracts) should be exactly what you're looking for.

Download 1990-2000 and 2000-2010.


Another option would be to work with normalized census boundaries, where data from the old geographies have been modified (split, combined, or apportioned as the case may be) to fit the most current boundaries. The Longitudinal Tract Data Base (LTDB) project at Brown University has normalized US census data from 1970 to 2000 to fit the current 2010 census geographies. They provide full documentation (plus the data) on their website:


Would save you the work of having to track and make changes yourself.

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