Here are a few words that surprisingly have not shown up through much of this debate: housing, mortgage, refinance, underwater.

It is striking that what had long been the weakest part of the economy -- the housing market – has been little featured in these debates. Housing is now making a modest recovery, one of the bright spots in economic growth.

It is not surprising – but perhaps disheartening – that the issue doesn't come up. Both Republicans and Democrats agree that one way to help the economy would be to launch a massive program to allow Americans to refinance their home loans at low rates. Obama has suggested such a proposal, as has a top adviser to Romney.

Yet neither Obama nor Romney has an incentive to discuss housing. Housing has been arguably one of Obama’s weakest areas as president; he has acknowledged it was the most stubborn problem he faced. And Romney’s approach has been largely to allow the free market to sort out the woes of the housing market, allowing those who got in over their heads to default.

Neither is a popular talking point.