When thinking about the strength of the Austin real estate market during normal times, there are three important variables that drive home values: population growth, job growth, and interest rates (you need to look separately at conforming and jumbo rates).While job growth does not seem to be occurring -- layoffs are being announced every week in Austin much like the rest of the country -- the other two variables are surprisingly strong.According to the Census Bureau, Austin/Round Rock was the 2nd-fastest-growing metropolitan area between 2007 and 2008. According to the Austin Business Journal, "the population in the . . .