Housing economists challenged the Federal Housing Finance Agency’s controversial stance against permitting Fannie Mae and Freddie Mac to allow principal forgiveness in loan modifications, telling U.S. senators this week that mortgage loan writedowns would go a long way to cure the ongoing housing crash and foreclosure crisis. Testifying before the Senate Committee on Banking, Housing and Urban Affairs, Moody’s Analytics Chief Economist Mark Zandi told lawmakers that government policy encouraging more mortgage modifications, particularly those involving “substantial principle writedowns” would...