RICHARDSON, TX—Across the 100 largest metro areas in the US, theasking rent gap between the top end and the bottom layer of theapartment market has widened to the point where it's essentiallydoubled, RealPage Inc. chief economist Greg Willett blogged earlierthis month. Specifically, Willett wrote, “the most expensive classA product now rents for $1,663 per month on average, basicallydouble the average $850 monthly rents for the lower priced class Cproperties.”

The gap is even greater on both coasts, and most especially inthe Northeast. Boston's class A rentals ask an average of $3,148per month, nearly triple the $1,1168 average for C product. It's alittle less steep in the New York City metro area, but only by afew percentage points. GlobeSt.com sounded out Willett for hisinsights on what's driving the stratification, and how rent growthis likely to progress in the next year or two.