HOW TO GOVERN AMERICA IN 2013 II: MORTGAGES, HOUSING, AND THE RECOVERY by DeLong

The claim that cuts in state and local (and federal!) spending are dragging down the economy are well-founded. The claim that mortgage debt overhang and depressed consumption are not dragging down the economy is not well-founded.

Baker says that right now: 

The claim is the dropoff in consumption due to the debt burden of these homeowners explains the weakness of the recovery.

Some simple arithmetic shows the absurdity of this view. The amount of underwater equity is estimated at between $700 billion (Core Logic) and $1.1 trillion (Zilliow). Suppose that we can disappear this debt through some decree, how much additional consumption would we see? If we assume that these households spend an incredibly large share of this increase in their net wealth, say 15 cents on the dollar, this would imply additional consumption of between $105 billion (Core Logic estimate) and $165 billion a year (Zillow estimate).

However we would have also destroyed the wealth of the mortgage holders. Let's assume that they just spend 2 cents on the dollar of their wealth. This would imply a net boost to demand of $91 billion to $143 billion. While this would be a helpful boost to the economy, equivalent to a government stimulus program of this size, this would hardly be sufficent to make up a shortfall in annual output that the Congressional Budget Office puts at close to $1 trillion.