A number of economists, myself included, have been talking for awhile about the underlying strength of the recovery in terms of "escape velocity." The idea we're trying to convey is a virtuous cycle of growth begetting jobs, which in turn generates incomes, which supports more growth, etc. So how would we know if we've achieved escape velocity? The first and one of most important things to look at is housing. True, it was a home price bubble that got us into this uniquely deep mess, but it's also the case that housing, goosed by low interest rates, is a traditional escape route from recession.