Policymakers at Fannie Mae, Freddie Mac and the FHA need to work with lenders to identify and resolve sources of buyback risk uncertainty in order to loosen the markets grip on tight credit conditions, according to a white paper issued this week by Moodys Analytics and the Urban Institute. Disagreements over lender judgment calls, post-underwriting chances in circumstances and nitpicking over trivial mistakes by the two government-sponsored enterprises and the FHA have stepped up put-backs in ways lenders cannot adequately address through better underwriting or pricing, note paper co-authors Mark Zandi and Jim Parrott. In 2011 and 2012, Fannie and Freddie together required...