Some excerpts on housing from San Francisco Fed President Janet Yellen:

It was housing of course that led the economy down. The great bust wiped out some $7 trillion in home values. In the second half of 2009 though, housing showed signs of stabilizing and I became hopeful that the sector would provide a significant boost to the economy this year. Now the market seems to have stalled. Home prices have been more or less stable since the middle of last year, but new home sales have resumed a downward slide and are at very low levels. Existing home sales spiked towards the end of last year in response to the homebuyer tax credit and have receded markedly since then. The credit expires this spring, removing an important prop. With sales still weak, builders have little incentive to ramp up home construction.

The continued high pace of foreclosures also creates risks to the recovery of the housing sector. Mortgage delinquencies and foreclosures are still rising as a consequence of the plunge in house prices over the past few years combined with high levels of unemployment. Despite the return to growth of the broader economy, we’ve seen no let-up in the pace at which borrowers are falling behind in their loans. Further additions to the already swollen stockpile of vacant homes represent a threat to house prices and new home construction activity.

It’s not always easy to understand the dynamics of the housing sector. Last year, for example, the share of mortgages that was 30 to 89 days past due declined. On the face of it, that looked like a hopeful sign. Unfortunately, when my staff examined the numbers more closely, it turned out that the drop actually represented a worsening of mortgage market conditions. What you want to see is delinquent borrowers becoming current. Instead, what happened was that delinquent mortgages moved in the other direction to an even poorer performance status. Many wound up in foreclosure. All in all, I expect that the share of loans that are seriously delinquent will continue to move higher. I am also concerned that we had a temporary reprieve in new foreclosures as the federal government’s trial modification program got under way. But not all of these modifications will stick, which means that some borrowers in the program could find themselves facing foreclosure again.

At the end of this month, the Fed will complete a large-scale program of purchases of mortgage-backed securities issued by Fannie Mae and Freddie Mac. Lenders sell mortgages to these two agencies, which package them as securities sold to investors. Last year, the Fed began buying these securities as part of a series of extraordinary measures to promote recovery. At the time the program was announced, mortgage spreads over yields on Treasury securities of comparable maturity were very high, reflecting in part the disruptions that had occurred in financial markets. I believe that our program worked to narrow those spreads, bringing mortgage rates down and contributing to the stabilization of the housing market. Financial markets have improved considerably over the last year, and I am hopeful that mortgages will remain highly affordable even after our purchases cease. Any significant run-up in mortgage rates would create risks for a housing recovery.