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.
Thanks!