By Alan Zibel

Does the Federal Reserve have good ideas for the housing market? That’s been the question since the Fed published its paper on housing last week.

Critics see the Fed’s foray into housing policy as an irresponsible deviation from the central bank’s mission of managing interest-rate policy. Supporters of more aggressive action to stabilize the housing market argue that the Fed is playing a valuable role in pushing the Obama administration and regulators to do more.

All of this debate ignores something that’s become increasingly clear: Due to practical and political limitations, changes to the government’s response to the foreclosure crisis are likely to involve tweaks on the margins rather than a massive revamp.

The Fed’s paper delved into detail about ways the Obama administration could encourage more “underwater” homeowners who owe more on their loans than their properties are worth to refinance at today’s ultra-low rates. Here are some issues to consider:

So what did the Fed suggest on refinancing?

In their paper, Fed officials suggested ways to further revamp a program launched in February 2009 that allowed homeowners with mortgages backed by government controlled mortgage-finance companies Fannie Mae and Freddie Mac to refinance if their properties have sunk dramatically in value.

The initiative, called Home Affordable Refinance Program, or HARP, is already being expanded under changes rolled out in October that have been dubbed HARP 2.0.

Why aren’t those changes sufficient?

Fed officials have applauded the changes rolled out by the Obama administration and the Federal Housing Finance Agency but say more could be done to both improve HARP and reach borrowers who currently aren’t eligible for the program. They say the program could be expanded to help an additional 1 million to 2.5 million homeowners who don’t have loans backed by Fannie or Freddie.

Doing so, however, is tougher than it sounds. As the Fed paper notes, Congress would need to change the rules by which Fannie and Freddie operate — an unlikely proposition the current environment of hyper-partisan gridlock.

By law, Fannie and Freddie are barred from buying new loans in which borrowers owe more than 80% of their home’s current value — unless the borrower pays for mortgage insurance. The HARP program allows those loans to be refinanced because Fannie or Freddie already guarantee them and are on tap for losses if the borrower defaults. But Fannie and Freddie are unlikely to be able to take on new “underwater” loans that they did not already guarantee.

The Fed paper, however, argues that allowing these borrowers to refinance through HARP would aid the economy and housing market, and therefore benefit Fannie and Freddie. Allowing those homeowners to refinance could reduce borrower’s payments “potentially reducing pressure on the housing market,” the Fed paper said.

What would expanding refinancing further mean for Fannie and Freddie?

Doing so would require a “potentially large” expansion of Fannie and Freddie’s balance sheet. That’s likely to be a tough sell at a time when many policy makers want to deemphasize Fannie and Freddie. “This may be the most politically unpalatable of the recommendations,”” wrote Rob Rowan, an analyst with Fitch Ratings.

Furthermore, a massive refinancing proposal, which has long been rumored, is unlikely to come to pass, largely because it could dry up investment in the market for mortgage-backed securities, which needs to keep humming so Americans can obtain home loans.

What else did the Fed propose?

The Fed paper also suggested some more tweaks. Regulators further reduce fees that Fannie and Freddie charge for higher-risk borrowers who refinance (those fees were already cut in the October announcement).

Fannie and Freddie could also “more comprehensively” waive their right to send back defaulted bad loans to lenders if they are refinanced through HARP. The paper noted that Fannie has taken steps to streamline refinancing by reducing that “putback” risk for all loans — including borrowers who owe less than 80% of their home’s current value. Establishing the same requirements for Fannie and Freddie, the paper said, “could facilitate more refinancing among this group of borrowers.”

Brad German, a Freddie Mac spokesman, defended his company’s policy. “We believe we have struck a balance where we are providing a streamlined refinance opportunity for borrowers while also maintaining our rights as investors to enforce quality,” he said