[Lobotomizer]

Austin and San Antonio will never be a single MSA, nor combined into a CSA

However, for the sake of discussion there are some interesting points to consider.

These are two of the fastest growing metros in the country, and have been for sometime. 100K annual increase in population is common.

The two counties between them, Hays and Comal, are some of the fastest growing in the nation. The towns between them, Kyle, San Marcos, and New Braunfels in particular, have experienced explosive growth.

I do not believe there is enough commuting between the two to ever be a single metro, but anectodally speaking I know there is a whole of traveling between the two for work, but primarily for entertainment. Having another major city 90 minutes, more or less depending on location, and their ammenities is nice. This is especially true for those between the two cities, such as in San Marcos where it really is just a hop, skip, and a jump into either city.

As far as the creation of a CSA, I actually believe it is much more likely the Austin-Killeen CSA could one day be formed. This would add about half a million to Austin's metro.