:::::Thanks. I agree it is a mess of definitions, none of which are ideal. "Metro area" is typically synonymous with MSA in the United States. For example, if you look at this list, the source for the U.S. metro area data is the Census MSA data. CSA isn't a very good substitute measure in my opinion – for example, they lump Baltimore in with Washington, DC. And Los angeles ends up getting almost everything in Southern California save for San Diego County. My preferred measure of city masses is this one, although most of the data are from non-government sources. 

 :::::One thing we could do is sum the SF and SJ metro areas figures for both population and GMP, and then make a note of it below. But it seems a little contrived and I don't see any reason why readers couldn't just do this themselves if they happened to want to know the number of people living beside the SF Bay while reading this article.