The census stuff is always something of a mystery to me.
For example, if you look at the 2nd table at this website,
Annual Estimates of the Population of Metropolitan and Micropolitan Statistical Areas , it indeed does show the Oklahoma City - Shawnee Combined Statistical Area at
1,262,027.
But, when you go to the "Counties" area here,
Annual Estimates of the Population for Counties: April 1, 2000 to July 1, 2007 , open the spreadsheet, one finds that the following counties in the estimate for what I presume is the Okc-Shawnee MSA are ...
Canadian........103,559
Cleveland........236,452
Grady..............50,615
Lincoln.............32,272
Logan..............36,435
Oklahoma........701,807
Pottawatomie....69,038
Total..........
1,230,178
In other words, I don't understand. The MSA number greater than the sum of the county totals. Will someone explain, please?