The Federal Housing Finance Agency’s proposed tightening of rules for private mortgage insurers that do business with Fannie Mae and Freddie Mac is a “thoughtful effort,” but “modest changes” are required, conclude a trio of economists in a paper issued last week. Moody’s Analytics’ Mark Zandi and Chris deRitis and the Urban Institute’s Jim Parrott said that the FHFA’s Private Mortgage Insurance Eligibility Requirements “should succeed” in ensuring that private MI are strong counterparties to the GSEs, while serving as “a much improved bulwark against excessive risk” in the system.