Consistent METAREAs over time

The documentation for METAREA notes that “users can obtain relatively consistent samples for “top-level” metro areas across time by grouping records according to the first 3 METAREA digits.” When there are multiple METAREAs with the same top-level code in the same year, what is the appropriate way to combine them? For example, should population for Dallas-Fort Worth (METAREA = 1920) and Fort Worth-Arlington (METAREA = 1921) be summed in 2003 to compare it with Dallas-Fort Worth-Arlington (METAREA = 1922) in 2005+?

Also, is there a reason why there is often an overlap of changing METAREAs for a given top-level code in 2004? For example, in 2000-2003 there is only Dallas-Fort Worth and Fort-Worth Arlington for top-level code 192, in 2005+ there is only Dallas-Fort Worth-Arlington for top-level code 192, but in 2004 there is an observation for all three.


Summing METAREA codes by the first 3 digits is the proper method for forming (relatively) consistent samples. While the sum of METAREA values 1920, 1921, and 1922 will always be the Dallas-Fort Worth-Arlington metro area, keep in mind that the actual boundaries of these areas do change over time. Thus, the samples are not perfectly consistent.

Since the coding structure for METAREA was updated in May 2004, samples from January-April 2004 contain two codes for the Dallas-Forth Worth-Arlington metro area, while samples from May-Dec 2004 contain only one code.

Hope this helps.